Some standard content:
Ics 77. 140. 50
National Standard of the People's Republic of China
GB 712—2000
Hull structural steel
Published on April 11, 2000
Implemented on November 1, 2000
Published by the National Quality and Technical Supervision Bureau
GB712—2000
This standard adopts the latest unified requirements of the International Association of Classification Societies (IAASS) and is equivalent to the China Classification Society (CCS)>& Specification for Materials and Welding (1998 Edition), and is consistent with various ship regulations. Compared with the original standard, the main changes are as follows: 1. The specification range of steel plate thickness is expanded from 50 mm to 100 mm. mm. The thickness negative deviation is changed to 0.3mm.
High-strength steel adds A40.D40, E40.F40 steel grades, and the quality grade is increased to F grade. The impact test temperature is -60℃. The sulfur and phosphorus content of each grade of steel is reduced to no more than 0.035% (of which F grade is no more than 0.025%). Add TMCP (Thermo-Mechanical Contralled Procesging) temperature-deformation control delivery status. : Different impact test sampling batches are specified according to different quality grades, different purity, and different delivery states. This standard is implemented by the actual From this month on, GE712-1988 "Structural Steel for Hull" is adopted. This standard is sponsored by the National Metallurgical Industry and is under the jurisdiction of the National Technical Committee for Steel Standardization. This standard was drafted by the Municipal Institute of Metallurgical Industry, the Ship Inspection Bureau of the People's Republic of China, and Wuhan Iron and Steel Company. The main drafters of this standard are Tang Yifan, Zhang Jieping, Ke Shixuan, Zhao Jie, and Deng Xian. This standard was first issued in 1965, revised for the first time in July 1979, and revised for the second time in September 1988. 1 Scope National Standard of the People's Republic of China Structural Steel for Hull Structural gteel
GB7122000
Replaces GB712
This standard specifies the dimensions, shape, technical requirements, test methods, inspection rules, packaging, marking and plate certificate for hull structural steel.
This standard is applicable to the manufacture of light-weight steel and high-strength steel for ocean-going, coastal and inland navigation areas, including steel plates with a thickness of not more than 100mm and steel sections with a thickness or diameter of not more than 50mm. All hull structural steel (reliable steel) shall be produced by steel mills approved by the Ship Inspection and Quarantine Administration of the People's Republic of China or China Classification Society (hereinafter referred to as the Ship Inspection and Quarantine Administration).
2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of this standard, the versions shown are all valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest version of the following standards. Sampling method for chemical analysis of steel and allowable deviation of chemical composition of products GB/T 222--1984
GB/T 223.3-1988
GR/T 223.4-1988
GB/T 223.11-1991
GR/T 223.14--2000
GB/T 223.16--1991
CB/T 223.171989
GB/T 223. 1R—1994
Methods for Chemical Analysis of Iron, Steel and Alloy
Diantipyryl methane gravimetric method for determination of manganese content by ammonium nitrate oxidation volumetric method
Methods for Chemical Analysis of Iron, Steel and Alloy
Methods for Chemical Analysis of Iron, Steel and Alloy
Methods for Chemical Analysis of Iron, Steel and Alloy
Methods for Chemical Analysis of Iron, Steel and Alloy
Methods for Chemical Analysis of Iron and Alloy
Methods for Chemical Analysis of Iron and Alloy
GB/T 223.19—1989
GB/T 223.23—1994
GB/T 223.24—1994
GB/T 223.26—1989
GB/T 223. 27—1994
GB/T 223.361994
GB/T 223.401985
GB/T 223. 54 -1987
GB/T 223. 58--1987
GB/ T 223.59—1987
GB/T 223.60-1997
GB/T 223.61-1988
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
Methods for chemical analysis of iron, steel and alloys
New method for chemical analysis of iron, steel and alloys
Approved by the State Administration of Quality and Technical Supervision on April 11, 2000 by the extraction photometric method with vanadium reagent
Determination of titanium by chromotropic acid photometric method Domain
Diantipyryl methane photometric determination
Sodium thiosulfate separation-iodine determination of copper
New cuproline-triclinic methane extraction photometric determination of copper addition of diacetyl diacetyl spectrophotometric determination of brocade pad
Extraction separation of high diacetyl spectrophotometric determination of nickel iodine thiourea direct photometric determination of molybdenum
Sulfate-acetic acid butyl ketone benzene extraction photometric determination of molybdenum reduction distillation radium separation-neutralization titration determination Ammonia content
Determination of nitrogen by ion exchange separation-sulfuron photometric method Determination of nickel by flame atomic absorption spectrophotometric method Determination of manganese oxide by sodium nitrite titration Determination of phosphorus by manganese oxide phosphorus blue photometric method Determination of phosphorus content by high temperature acid dehydration method Determination of phosphorus content by ammonium phosphomolybdate method Implementation of 2000-11-01
GB/T GB/T 223.62—1988
GB/T 223.63—1988
GB 712—2000
Methods for chemical analysis of steel, iron and alloys
Methods for chemical analysis of steel, iron and alloys
GB/T 223.64--1988
Methods for chemical analysis of steel, titanium and alloys
Methods for chemical analysis of steel and alloys
GB/T 223.68—1997
GB/T 223.69—1997
GB/T 223.71-1997
GB/T 223.72—1991
GB/T 223.741997
GH/T 223.76—1994
GB/T 228——1987
GB/T 229-1994
GB/T 232—1999
GB/T 247—1997|| tt||GB/T 709—1988
CB/T 2101—1989
3 Classification and code
Methods for chemical analysis of steel and alloys
Methods for chemical analysis of steel and alloys
Methods for chemical analysis of steel and alloys
Chemical analysis methods for steel, iron and alloys
Chemical analysis methods for steel, iron and alloys
Metal tensile test method
Metal Charpy notched impact test method
Metal bending test method|| tt||Determination of phosphorus content by butyl acetate extraction spectrophotometry
Determination of phosphorus content by sodium (potassium) iodate spectrophotometry by manganese pad flame atomic absorption spectrometry
Iodic acid after combustion in a tube furnace Potassium titration method for determination of vegetable content Gas volumetric method for determination of carbon content after combustion in a tube furnace Gravimetric method for determination of carbon content after combustion in a tube furnace Alumina chromatography-barium sulfate gravimetric method for determination of sulfur uncombined carbon content Determination
Determination of vanadium content by flame atomic absorption harmonic method
General rules for acceptance, packaging, marking and quality certificate of steel plates and steel strips Size, shape, weight of hot-rolled steel plates and steel strips Acceptance, packaging, marking and quality certificate of steel with allowable deviations · General specification exceeds 3.1. Structural steel for hull is divided into two categories: general strength steel and high strength steel: general strength steel is divided into: A, B, D, E Quality grade: High-strength steel is divided into three strength levels and four quality grades: A32, D32. E32, F32, A36, T336, E36, F36, A40. D40, E40, F40. || tt || 4 Dimensions, shape, weight and allowable deviations
4.1 The dimensions, shape and allowable deviations (including thickness tolerance) of steel plates shall comply with the provisions of GB/T709, but the negative thickness deviation shall not exceed 0.3 mm.
4.1.1 Steel plates are delivered according to theoretical weight. With the consent of the purchaser and the negotiation between the supply and demand parties, the theoretical thickness based on the theoretical weight can be calculated by adding the nominal original thickness to the additional value. The calculation method of the thickness additional value is as follows: Thickness additional value = tolerance value/2-0.3 mm
Note: Tolerance value refers to the tolerance specified in GB/T 709, which is the absolute value of positive deviation plus negative deviation. 4.2 Dimensions, shape and weight of steel The allowable deviation shall comply with the relevant standards. 5 Technical Specifications
5.1 Chemical Composition
The chemical composition (melting composition) of high strength steel shall comply with the provisions of Table 1. Table 1
Steel grade
Chemical composition K
2≥2.5C
.0.35
0.80--1.20
0.60~-1.20
0.70--1,26
5.1.1.1 With the consent of the purchaser and specified in the contract, the thickness shall not exceed 12.5 For Grade A steel with a thickness of mm, rimmed steel may be used, but this should be noted on the quality certificate. GB712—2000 5.1.1.2 Expected minimum carbon content of steel The lower limit is determined by negotiation between the supply and demand parties. 5.1.1.3 The upper limit of carbon content in steel can be 0.23%. 5.1.1.4 The carbon equivalent of all quality grades of steel is C+1/GMn≤0.40%. 5.1.1.5 When the B grade is made for impact test, the lower limit of manganese content can be 0.60%. 5.1.1.6 Thickness For D-grade steel and E-grade steel with a mass of 25 μm, the total aluminum content can be determined instead of the acid-soluble aluminum content. In this case, the total aluminum content should not be less than 0.020%. Other refined grains can also be used with the consent of the ship inspection department. Elements, 5.1.1.7 It is recommended to deliver the steel in the temperature controlled deformation rolling (TMCP) state. With the approval of the ship inspection department, the chemical composition may be different from the specifications in Table 1.
5.1.1.8 The copper content in steel should not exceed 0.35%. The chromium and nickel content should not exceed (0.30%). 5.1.1.9 To improve the performance of steel, If other trace elements are added during processing, they should be indicated on the quality certificate. 5.1.2 The chemical composition (melting composition) of high-strength steel should comply with the provisions of Table 2. Table 2
Steel Grade| |tt||Chemical composition%
A32 A36 A10 D32 D36 EM0 E32 E36 E100.18
0.90--1.60
0.02~0.05
( . 05--0, 10
The lower limit of carbon content of the product shall be determined by negotiation between the supplier and the buyer. 5. 1. 2. 1
5- 1- 2.2
5. 1. 2. 3
Grade A steel with a thickness not exceeding 12.5 mm - the lower limit of Mn content in the wall can be up to 0.70% . Fa2F36F40
.0.50
0.90--1.60
.0.025
n.02 ~ (1.F5
0 . 05--0. [0
.0. 02
.0.00m
(0.12 when containing A1)
can determine the total aluminum content (AIt) instead of the acid-soluble pliers (Als) content. At this time, Alt should Not less than 0.02%. 5.1.2.4 Trace elements such as NL, V, Ti, etc. specified in Table 2 may be added individually or in any combination. When added individually, their content shall not be less than the lower limit specified in the specification. When two or more of the two are mixed, the total content shall not be greater than (0.12%. 5.1-2.5 If the steel is delivered in the temperature-deformation controlled rolling state, the chemical composition may be different from the provisions of Table 2 below with the approval of the ship inspection department. 5.1.2.6 In order to improve the performance of the steel, other trace amounts are added during the smelting process. 5.1.2.7 Carbon equivalent is generally not more than 0.10%. If magnetic equivalent is more than 0.10%, it should be noted in the quality certificate. Carbon equivalent is calculated according to the formula ( 1) Calculation: en (%) =- t - Mn/6- (C -- Mo . V)/5 (Ni Cu)/15............ 1)5.1.2.8 Steel delivered in TMCP state, carbon The equivalent should comply with the provisions of Table 3, but F32 in the table is not applicable to thickness greater than 50mm. 3
Collar grade
A32D32E32F32
A36T36F36F36
A40 D40 E40 F40| |tt||5.2 Delivery status
GB 712—2000
Equivalent weight Ceg,% not more than
Original thickness mm
1- Delivery status of general strength steel It shall comply with the requirements of Table 4.5.2. 1
Steel material grade
Delivery status
Compliance, m
2~25~35
N(piece), TM per piece）
R(25),TM(25).AR * (15),CR +(15) Inspection status: A+NIE fire ICR controlled rolling: TM (TMCP) flow-deformation controlled rolling: AR+ ship inspection and adjustment, can be delivered with hot rolling+R* New inspection department Xiang Hui, can use controlled rolling delivery 50 ~ ~ 100 | | tt | | 35- ~ 50 | | tt | | CR (503 | | tt | | TM (50) | | tt | | CR ( sO)
TM(EO)
AR(25)
>50:-100
N(-),TM(||t t||CR(50)
AR*(50)
N(50),TM(50)
CR(50)
AR*(25)
CR(25)
2 Grade A steel sheets with a thickness of >50~100mm are delivered in TM state and grade n steel sections with a thickness of >35~50mm are delivered in hot-rolled state. The lead inspection department agrees that the values in brackets (15, 25, 50) represent the sample batch for impact test. The unit of the values in brackets (15, 25, 50) is t (ton). (I) means no impact test Test 5.2.2 The delivery state of high-strength steel shall comply with the provisions of Table 5. 5.3 Mechanical properties
5.3.1 The mechanical properties of steel shall comply with the provisions of Table 6. 4
Steel grade refinement element
N+V or V
AI or Al:+Ti
Nh+V or V
Al or AI+Ti
Product type
Plate, profile
Plate, profile
Delivery status:A,N,Normalizing#
CR Controlled rolling1
GB 712—2000
Delivery status
Thickness,mm
12.5-12.5~20~20~2525~35>35~50A(50)
N(50),Cr(50).TM(50)
N(50),Cr(50).TM(5D),AR + (25)A (50) | ||N(50),CR(50).TM(50).AR - (35)A(50)
AR + (25)
N(50).CR(50).TM(50)
N(50)+CR(50).
TMt50),AR + (25)
N:50).CR(50).TM(50)
N(each piece),TM(each piece)
N(25),TM(25),AR+(15),CR(15)
N(each piece),TM(year piece),QT(each heat treatment length)N(25).TM(25),QT(25)
N(each piece),TM(each piece),QT(each heat treatment length)N(25).TM(25),QT(25).CR - (25)N(each piece),TM(each piece),QT(mother-heat treatment length adjustment)N(25),TM(25).QT(25)
TM Temperature-deformation control rolling drama;
QT annealing and tempering;
AR *After inspection by the inspection department, the product is delivered in hot rolled state, 50~100
N(50),CR(253).TM(50)
N(50),CR(25).TM(50)
N(50),CR(25).TM(50)
N(50),CR(25),TM(5U)
2 The numerical value in the bracket indicates the batch range for the impact test. The value in the number (15, 25, 50> is in the unit of 15
Service point
Not small
Tensile strength
400--520
440--570
490--630
510-660
GB 712—2000
Impact energy A, J
Elongation
Not less than
— 20
— 60
Thickness, mm
50--70
1With the approval of the ship inspection department, the upper limit of the tensile strength of the A-level type can exceed the provisions of Table 6. 5. 3. 1. 1
Not less than
70--100
Charpy (V-notch) impact energy, based on the half-mean of three specimens, the single value of one specimen is allowed to be lower than the value specified in Table 6. 5. 3. 1. 2
But not less than 7% of the specified value,
5.3.1.3Except for the requirements of the purchaser, the impact test is only carried out in the longitudinal direction, but the supplier adopts the belt to ensure the transverse impact performance,5.3.1.4Grade steel with a thickness of less than 125mm may not be subjected to impact test with the consent of the ship inspection department5. 3. 1. 5Grade A steel with a thickness greater than 50mm, if it has been processed with refined grains and delivered in a normalized state, may not be subjected to impact test. With the consent of the ship inspection department, Grade A steel delivered in a temperature-deformation controlled conversion state may also not be subjected to impact test. 5.3.1.6If the supplier can guarantee, with the consent of the ship inspection department, A32 and A36 may not be subjected to punch-out test. 5.3.2Steel with a thickness of less than 12mm shall use small-size specimens for impact test, and the minimum average impact energy shall comply with the provisions of Table 7.丧7
Small specimen size
Small specimen size
GB 712
Table 7 (End)
5.3.3 Cold bending test: For Grade A steel, perform 80% cold bending (b=2α) with a core diameter of 24; for Grade B, D, E and high-strength steel, perform 120° wide cold bending (6-54) with a core diameter of 3α. If the supplier can guarantee this, the cold bending test may not be performed. 5.3. 4 The tensile strength of thin steel with a thickness of 2~-4 mm may exceed that specified in Table 6, and the elongation after fracture is allowed to have a reduced resistance value (absolute value) as specified in Table 8.
Thickness of steel plate, mm
3. 0--3. 5
≥3. 3~4. 0
lower value,
5.4, the grain size of E-grade steel and high-strength steel shall not be less than Grade 5. If the supplier can guarantee it, no inspection is required. 5.5 The surface of the steel plate is not allowed to have bubbles, scars, cracks, rips, folds, imperfections and pressed iron oxide scale. The steel plate shall not be delaminated. The surface of the steel plate is allowed to have a thin layer of iron oxide scale, rust, inconspicuous roughness caused by pressed iron oxide scale and rolling, mesh, scratches and other local defects that do not hinder the inspection of surface defects, but the depth shall not exceed half of the negative deviation, and the minimum thickness of the steel plate shall be guaranteed. The surface defects of the steel plate can be repaired and cleaned, but the minimum degree of the steel plate shall be guaranteed, and the cleaned area shall be smooth and without edges and corners. The surface quality of steel shall comply with the relevant provisions of the standards for hot-rolled bars of low-alloy structural steel. 6 Test methods 6.1 The inspection items, sampling quantity, sampling method and test method of each batch of steel shall comply with the provisions of Table 9. Table 9 Test items Chemical analysis Charpy (V-notch), impact, low manganese impact Item Sample quantity (for each steel number) Sampling method GB/T 222 GB/T 2975 The sampling position of each batch of steel plates, angle steels, channel steels and ball steels shall comply with the provisions of GB/T2975. 6.2 T-shaped steels shall be cut at 1/3 of the width from one side. Round steel should be cut at 1/3 radius from the outside. Acceptance rules
7.1 The acceptance of steel shall be carried out by the technical supervision department of the party. Test method
GB/T223
.GB/T228
GB/T 232
GR 229
GB/T 22S
GB 712—2000
2 Steels shall be made of the same furnace number, the same specification (model), the same rolling system, and the same heat treatment system. The weight of each batch shall not exceed 50t.
If controlled rolling is allowed instead of normalizing steel, the weight of each batch shall not exceed 25t. The batch size for impact test sampling shall comply with the quantity specified in the brackets of Table 4 and Table 5. 7.3 If the impact strength of the Charpy V-notch low-temperature impact test is lower than the average value specified in Table 6, no more than 2 samples will be lower than the average value, and no more than 1 sample will be lower than 70% of the average value. A group of three samples can be taken from the same steel or the same sample for testing. The average value of the two groups of 6 samples shall not be lower than the specified value. Two samples are allowed to be lower than the specified value, and only one sample is allowed to be lower than 70% of the specified value.
7.4 The re-inspection of other items shall comply with the provisions of GB/T247 and GB/T2101. 8 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel plates and types shall comply with the relevant provisions of GB/T247 and GB/T2101.AR *125)
N(50),CR(50),TM(50)
N(50),CR(50)+TM(50)
N(50 ),CR(50).TM(50).AR - (35)A(50)
AR + (25)
N(50).CR(50).TM(50)
N(50)+CR(50).
TMt50),AR + (25)
N:50).CR(50).TM(50)
N(each),TM(each)
N(25),TM( 25),AR+(15),CR(15)
N (each piece),TM(yearly pieces),QT(each heat treatment length)N(25).TM(25),QT(25 )
N(each piece),TM(each piece),QT(each heat treatment length)N(25).TM(25),QT(25).CR - (25)N(each piece) ,TM (each piece),QT (mother-heat treatment length adjustment)N(25),TM(25).QT(25)
TM Transformation-deformation control rolling drama;
QT Pants fire and tempering;
AR * After inspection by the cancer inspection department, it is delivered in hot milk state, 50~100
N(50),CR(253.TM(50)
N(50),CR25).TM (50)
N(50),CR(25).TM(50)
N(50),CR(25),TM(5U)
2 The numerical value represents the number of machines to be tested for the impact test. The unit of the teaching value (15, 25, 50> is 15
service point
not small Ding||tt| |Tensile strength
400--520
440--570
490--630
510-660
GB 712—2000
Impact energy A, J
Elongation
Not less than
— 20
— 60
Thickness, mm
50--70
1 With the approval of the ship inspection department, the upper limit of the tensile strength of the Class A type can exceed the provisions of Table 6. 5.3.1.1
No Less than
70--100
Charpy (V-notch) impact energy, based on the half-mean of three specimens, it is allowed that the single value of one of the specimens is lower than the value specified in Table 6. 5. 3. 1. 2
But it shall not be less than 7% of the specified value,
5.3.1.3Except for the requirements of the purchaser, the impact test shall only be carried out in the longitudinal direction, but the supplier shall adopt the belt to ensure the transverse impact performance, 5.3. 1.4 Grade A steel with a thickness less than 125 mm may not be subjected to impact test with the approval of the ship inspection department. 5.3.1.5 Grade A steel with a thickness greater than 50 mm, if it has been processed with refined grains and delivered in normalized state, , impact test may not be conducted. With the approval of the ship inspection department, A-grade steel delivered in the temperature-deformation controlled conversion state may also not be subjected to impact test. 5.3.1.6 If the supplier can guarantee, with the approval of the ship inspection department, A32 and A36 5.3.2 For steel with a thickness less than 12 mm, a small-sized specimen shall be used for impact test, and the minimum average impact energy shall comply with the requirements of Table 7. Table 7 (end) 5.3.3 Cold bending test: A Grade steel is cold bent (b=2α) 80% with a core diameter of 24; Grade B, D, E steel and high-strength steel are cold bent (6-54) 120° with a core diameter of 3α If the supplier can guarantee this, the cold bending test may not be performed. 5.3.4 The tensile strength of thin steel with a thickness of 2 to 4 mm may exceed the requirements of Table 6, and the elongation after fracture may have a reduced value (absolute value) as shown in Table 8. ).
Thickness of steel plate, mm
3. 0--3. 5
≥3. 3~4. 0
Lowest value,
5.4. The grain size of E-grade steel and high-strength steel shall not be less than Grade 5. If the supplier can guarantee this, no inspection is required. 5.5 The surface of the steel plate shall not have bubbles, scars, cracks, rips, folds, impurities or pressure. Iron oxide scale. The steel plate shall not be delaminated. The surface of the steel plate is allowed to have a thin layer of iron oxide scale, rust, inconspicuous roughness caused by pressing iron oxide scale and rolling, mesh, scratches and other Local defects, but their depth shall not exceed half of the negative deviation, and the minimum thickness of the steel plate shall be guaranteed. Surface defects of steel plates can be cleaned by grinding, but the minimum thickness of the steel plate shall be guaranteed, and the cleaned area shall be smooth without edges and corners. The surface quality of steel sections shall comply with the relevant provisions of the standards for cable-embedded structural steel and low-alloy structural steel hot-rolled bars. 6 Test methods
6.1 The inspection items, sampling quantity, sampling method and test method for each batch of steel shall be Meet the requirements of Table 9. Table 9
Rubber test items
Chemical analysis
Charpy (V-notch), impact
Low manganese impact
Sample quantity (each batch number) Sample method GB/T 222 GB/T 2975 Each batch of steel plates The sampling locations of angle steel, slot steel and ball steel shall comply with the provisions of GB/T2975. 6.2
T-shaped steel shall be cut at 1/3 of the width of one side. Round steel should be cut at 1/3 radius from the outside. Acceptance rules
7.1 The acceptance of steel is carried out by the technical supervision department of the party. Test method
GB/T223
.GB/ T228
GB/T 232
GR 229
GB/T 22S
GB 712—2000
2Steel should be made of the same furnace number and the same Specifications (types), the same rolling system, the same heat treatment system grouped into a batch, each batch weight shall not be greater than 50t. The weight shall not exceed 25t. The batch size for the impact test shall comply with the quantity specified in brackets in Table 4 and Table 5. 7.3 If the impact strength of the Charpy V-notch low temperature impact test is lower than the average value specified in Table 6, no more than 2 specimens shall be lower than the average value, and no more than 1 specimen shall be lower than 70% of the average value. Take another group of three samples from the same steel or the same sample for testing. The average value of the six samples in the two groups before and after shall not be lower than the specified value. Two samples are allowed to be lower than the specified value. Only one sample with a value of 70% is allowed.
7.4 The retest of other items shall comply with the provisions of GB/T247 and GB/T2101. 8 Packaging, marking and quality certificate
Steel plates and The packaging, marking and quality certificate of this type shall comply with the relevant provisions of GB/T247 and GB/T2101.AR *125)
N(50),CR(50),TM(50)
N(50),CR(50)+TM(50)
N(50 ),CR(50).TM(50).AR - (35)A(50)
AR + (25)
N(50).CR(50).TM(50)
N(50)+CR(50).
TMt50),AR + (25)
N:50).CR(50).TM(50)
N(each),TM(each)
N(25),TM( 25),AR+(15),CR(15)
N (each piece),TM(yearly pieces)),QT(each heat treatment length)N(25).TM(25),QT(25 )
N(each piece),TM(each piece),QT(each heat treatment length)N(25).TM(25),QT(25).CR - (25)N(each piece) ,TM (each piece),QT (mother-heat treatment length adjustment)N(25),TM(25).QT(25)
TM Transformation-deformation control rolling drama;
QT Pants fire and tempering;
AR * After inspection by the cancer inspection department, it is delivered in hot milk state, 50~100
N(50),CR(253.TM(50)
N(50),CR25).TM (50)
N(50),CR(25).TM(50)
N(50),CR(25),TM(5U)
2 The numerical value represents the number of machines to be tested for the impact test. The unit of the teaching value (15, 25, 50> is 15
service point
not small Ding||tt| |Tensile strength
400--520
440--570
490--630
510-660
GB 712—2000
Impact energy A, J
Elongation
Not less than
— 20
— 60
Thickness, mm
50--70
1 With the approval of the ship inspection department, the upper limit of the tensile strength of the Class A type can exceed the provisions of Table 6. 5.3.1.1
No Less than
70--100
Charpy (V-notch) impact energy, based on the half-mean of three specimens, it is allowed that the single value of one of the specimens is lower than the value specified in Table 6. 5. 3. 1. 2
But it shall not be less than 7% of the specified value,
5.3.1.3Except for the requirements of the purchaser, the impact test shall only be carried out in the longitudinal direction, but the supplier shall adopt the belt to ensure the transverse impact performance, 5.3. 1.4 Grade A steel with a thickness less than 125 mm may not be subjected to impact test with the approval of the ship inspection department. 5.3.1.5 Grade A steel with a thickness greater than 50 mm, if it has been processed with refined grains and delivered in normalized state, , impact test may not be performed. With the approval of the ship inspection department, A-grade steel delivered in the temperature-deformation controlled conversion state may also not be subjected to impact test. 5.3.1.6 If the supplier can guarantee, with the approval of the ship inspection department, A32 and A36 5.3.2 For steel with a thickness less than 12 mm, a small-sized specimen shall be used for impact test, and the minimum average impact energy shall comply with the requirements of Table 7. Table 7 (end) 5.3.3 Cold bending test: A Grade steel is cold bent (b=2α) 80% with a core diameter of 24; Grade B, D, E steel and high-strength steel are cold bent (6-54) 120° with a core diameter of 3α If the supplier can guarantee this, the cold bending test may not be performed. 5.3.4 The tensile strength of thin steel with a thickness of 2 to 4 mm may exceed the requirements of Table 6, and the elongation after fracture may have a reduced value (absolute value) as shown in Table 8. ).
Thickness of steel plate, mm
3. 0--3. 5
≥3. 3~4. 0
Lowest value,
5.4. The grain size of E-grade steel and high-strength steel shall not be less than Grade 5. If the supplier can guarantee this, no inspection is required. 5.5 The surface of the steel plate shall not have bubbles, scars, cracks, rips, folds, impurities or pressure. Iron oxide scale. The steel plate shall not be delaminated. The surface of the steel plate is allowed to have a thin layer of iron oxide scale, rust, inconspicuous roughness caused by pressing iron oxide scale and rolling, mesh, scratches and other Local defects, but their depth shall not exceed half of the negative deviation, and the minimum thickness of the steel plate shall be guaranteed. Surface defects of steel plates can be cleaned by grinding, but the minimum thickness of the steel plate shall be guaranteed, and the cleaned area shall be smooth without edges and corners. The surface quality of steel sections shall comply with the relevant provisions of the standards for cable-embedded structural steel and low-alloy structural steel hot-rolled bars. 6 Test methods
6.1 The inspection items, sampling quantity, sampling method and test method for each batch of steel shall be Meet the requirements of Table 9. Table 9
Rubber test items
Chemical analysis
Charpy (V-notch), impact
Low manganese impact
Sample quantity (each batch number) Sample method GB/T 222 GB/T 2975 Each batch of steel plates The sampling locations of angle steel, slot steel and ball steel shall comply with the provisions of GB/T2975. 6.2
T-shaped steel shall be cut at 1/3 of the width of one side. Round steel should be cut at 1/3 radius from the outside. Acceptance rules
7.1 The acceptance of steel is carried out by the technical supervision department of the party. Test method
GB/T223
.GB/ T228
GB/T 232
GR 229
GB/T 22S
GB 712—2000
2Steel should be made of the same furnace number and the same Specifications (types), the same rolling system, the same heat treatment system grouped into a batch, each batch weight shall not be greater than 50t. The weight shall not exceed 25t. The batch size for the impact test shall comply with the quantity specified in brackets in Table 4 and Table 5. 7.3 If the impact strength of the Charpy V-notch low temperature impact test is lower than the average value specified in Table 6, no more than 2 specimens shall be lower than the average value, and no more than 1 specimen shall be lower than 70% of the average value. Take another group of three samples from the same steel or the same sample for testing. The average value of the six samples in the two groups before and after shall not be lower than the specified value. Two samples are allowed to be lower than the specified value. Only one sample with a value of 70% is allowed.
7.4 The retest of other items shall comply with the provisions of GB/T247 and GB/T2101. 8 Packaging, marking and quality certificate
Steel plates and The packaging, marking and quality certificate of this type shall comply with the relevant provisions of GB/T247 and GB/T2101.TM(5U)
2 The numerical value in brackets indicates the range of batches for impact test. The unit of the value in number (15, 25, 50> is 15
Service point
Not less than
Tensile strength
400--520
440--570
490--630
510-660
GB 712—2000
Impact energy A, J
Elongation
Not less than
— 20
— 60
Thickness, mm
50--70
1 With the approval of the ship inspection department, the upper limit of tensile strength of Class A type can exceed the provisions of Table 6, 5. 3.1.1
Not less than
70--100
Charpy (V-notch) impact energy, based on the half mean of three specimens, the single value of one of the specimens is allowed to be lower than the value specified in Table 6, 5.3.1.2
But not less than 7% of the specified value,
5.3.1.3 Unless otherwise required by the purchaser, the impact test is only carried out in the longitudinal direction, but the supplier adopts belt to ensure the transverse impact performance, 5.3.1.4 For grade steel with a thickness of less than 125mm, the impact test may not be carried out with the consent of the ship inspection department. 5.3.1.5 For steel with a thickness of more than 50 mm, if the A-grade steel is delivered in a normalized state after grain refinement, impact test may not be performed. With the approval of the ship inspection department, the A-grade steel delivered in a temperature-deformation controlled conversion state may also be exempted from impact test. 5.3.1.6 If the supplier can guarantee, with the approval of the ship inspection department, A32 and A36 may not be subjected to punchout test. 5.3.2 For steel with a thickness of less than 12 mm, small-size specimens are used for impact test, and the minimum average impact energy shall comply with the provisions of Table 7. 丧7
Small specimen size
Small specimen size
GB 712
Table 7 (end)
5.3.3 Cold bending test: Grade A steel is subjected to traction cold bending (b=2α) with a bending core diameter of 80%; Grade B, D, E steel and high-strength steel are subjected to wide cold bending (6-54) with a bending core diameter of 120° and a bending core diameter of 3α. If the supplier can guarantee this, the cold bending test may not be performed. 5.3. 4 The tensile strength of thin steel with a thickness of 2~-4 mm may exceed the requirements of Table 6, and the elongation after fracture is allowed to have a reduced value (absolute value) as shown in Table 8. bzxz.net
Thickness of steel plate, mm
3. 0--3. 5
≥3. 3~4. 0
low value,
5.4, E-grade steel and high-strength steel grain size should not be less than 5 grades. If the supplier can guarantee, no inspection is required. 5.5 The surface of the steel plate is not allowed to have bubbles, scars, cracks, rips, folds, imperfections and pressed iron scale. The steel plate shall not be delaminated. The surface of the steel plate is allowed to have a thin layer of iron scale, rust, inconspicuous roughness caused by pressed iron scale and rolling, mesh, scratches and other local defects that do not hinder the inspection of surface defects, but the depth shall not exceed half of the negative deviation, and the minimum thickness of the steel plate shall be guaranteed. The surface defects of the steel plate are allowed to be repaired and cleaned, but the minimum degree of the steel plate shall be guaranteed, and the cleaned area shall be smooth and without edges and corners. The surface quality of the steel section shall comply with the relevant provisions of the standards for cable-embedded structural steel and hot-rolled bars of low-alloy structural steel. 6 Test method
6.1 The inspection items, sampling quantity, sampling method and test method of each batch of steel shall comply with the provisions of Table 9. Table 9 Test items Chemical analysis Charpy (V-notch), impact test Low manganese impact test Item Sample quantity (for each product) Sampling method GB/T 222 GB/T 2975 The sampling position of each batch of steel plates, angle steels, groove steels and ball steels shall comply with the provisions of GB/T 2975. 6.2 T-shaped steels shall be cut at 1/3 of the width from one side. Round steels shall be cut at 1/3 of the radius from the outside. Acceptance rules 7.1 The acceptance of steel products shall be carried out by the technical supervision department of the party. Test method
GB/T223
.GB/T228
GB/T 232
GR 229
GB/T 22S
GB 712—2000
2 Steels shall be made from the same furnace number, same specification (model), same rolling system, and same heat treatment system. The weight of each batch shall not exceed 50t.
If controlled rolling is allowed to replace normalized steels, the weight of each batch shall not exceed 25t. The batch size for impact test shall comply with the quantity specified in the brackets of Table 4 and Table 5. 7.3 If the impact strength of the Charpy V-notch low-temperature impact test is lower than the average value specified in Table 6, no more than 2 samples will be lower than the average value, and no more than 1 sample will be lower than 70% of the average value. A group of three samples can be taken from the same steel or the same sample for testing. The average value of the two groups of 6 samples shall not be lower than the specified value. Two samples are allowed to be lower than the specified value, and only one sample is allowed to be lower than 70% of the specified value.
7.4 The re-inspection of other items shall comply with the provisions of GB/T247 and GB/T2101. 8 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel plates and types shall comply with the relevant provisions of GB/T247 and GB/T2101.TM(5U)
2 The numerical value in brackets indicates the range of batches for impact test. The unit of the value in number (15, 25, 50> is 15
Service point
Not less than
Tensile strength
400--520
440--570
490--630
510-660
GB 712—2000
Impact energy A, J
Elongation
Not less than
— 20
— 60
Thickness, mm
50--70
1 With the approval of the ship inspection department, the upper limit of tensile strength of Class A type can exceed the provisions of Table 6, 5. 3.1.1
Not less than
70--100
Charpy (V-notch) impact energy, based on the half mean of three specimens, the single value of one of the specimens is allowed to be lower than the value specified in Table 6, 5.3.1.2
But not less than 7% of the specified value,
5.3.1.3 Unless otherwise required by the purchaser, the impact test is only carried out in the longitudinal direction, but the supplier adopts belt to ensure the transverse impact performance, 5.3.1.4 For grade steel with a thickness of less than 125mm, the impact test may not be carried out with the consent of the ship inspection department. 5.3.1.5 For steel with a thickness of more than 50 mm, if the A-grade steel is delivered in a normalized state after grain refinement, impact test may not be performed. With the approval of the ship inspection department, the A-grade steel delivered in a temperature-deformation controlled conversion state may also be exempted from impact test. 5.3.1.6 If the supplier can guarantee, with the approval of the ship inspection department, A32 and A36 may not be subjected to punchout test. 5.3.2 For steel with a thickness of less than 12 mm, small-size specimens are used for impact test, and the minimum average impact energy shall comply with the provisions of Table 7. 丧7
Small specimen size
Small specimen size
GB 712
Table 7 (end)
5.3.3 Cold bending test: Grade A steel is subjected to traction cold bending (b=2α) with a bending core diameter of 80%; Grade B, D, E steel and high-strength steel are subjected to wide cold bending (6-54) with a bending core diameter of 120° and a bending core diameter of 3α. If the supplier can guarantee this, the cold bending test may not be performed. 5.3. 4 The tensile strength of thin steel with a thickness of 2~-4 mm may exceed the requirements of Table 6, and the elongation after fracture is allowed to have a reduced value (absolute value) as shown in Table 8.
Thickness of steel plate, mm
3. 0--3. 5
≥3. 3~4. 0
low value,
5.4, E-grade steel and high-strength steel grain size should not be less than 5 grades. If the supplier can guarantee, no inspection is required. 5.5 The surface of the steel plate is not allowed to have bubbles, scars, cracks, rips, folds, imperfections and pressed iron scale. The steel plate shall not be delaminated. The surface of the steel plate is allowed to have a thin layer of iron scale, rust, inconspicuous roughness caused by pressed iron scale and rolling, mesh, scratches and other local defects that do not hinder the inspection of surface defects, but the depth shall not exceed half of the negative deviation, and the minimum thickness of the steel plate shall be guaranteed. The surface defects of the steel plate are allowed to be repaired and cleaned, but the minimum degree of the steel plate shall be guaranteed, and the cleaned area shall be smooth and without edges and corners. The surface quality of the steel section shall comply with the relevant provisions of the standards for cable-embedded structural steel and hot-rolled bars of low-alloy structural steel. 6 Test method
6.1 The inspection items, sampling quantity, sampling method and test method of each batch of steel shall comply with the provisions of Table 9. Table 9 Test items Chemical analysis Charpy (V-notch), impact test Low manganese impact test Item Sample quantity (for each product) Sampling method GB/T 222 GB/T 2975 The sampling position of each batch of steel plates, angle steels, groove steels and ball steels shall comply with the provisions of GB/T 2975. 6.2 T-shaped steels shall be cut at 1/3 of the width from one side. Round steels shall be cut at 1/3 of the radius from the outside. Acceptance rules 7.1 The acceptance of steel products shall be carried out by the technical supervision department of the party. Test method
GB/T223
.GB/T228
GB/T 232
GR 229
GB/T 22S
GB 712—2000
2 Steels shall be made from the same furnace number, same specification (model), same rolling system, and same heat treatment system. The weight of each batch shall not exceed 50t.
If controlled rolling is allowed to replace normalized steels, the weight of each batch shall not exceed 25t. The batch size for impact test shall comply with the quantity specified in the brackets of Table 4 and Table 5. 7.3 If the impact strength of the Charpy V-notch low-temperature impact test is lower than the average value specified in Table 6, no more than 2 samples will be lower than the average value, and no more than 1 sample will be lower than 70% of the average value. A group of three samples can be taken from the same steel or the same sample for testing. The average value of the two groups of 6 samples shall not be lower than the specified value. Two samples are allowed to be lower than the specified value, and only one sample is allowed to be lower than 70% of the specified value.
7.4 The re-inspection of other items shall comply with the provisions of GB/T247 and GB/T2101. 8 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel plates and types shall comply with the relevant provisions of GB/T247 and GB/T2101.1 The inspection items, sampling quantity, sampling method and test method of each batch of steel products shall comply with the provisions of Table 9. Table 9 Inspection items Chemical analysis Charpy (V-notch), impact Low manganese impact Item Sample quantity (for each batch) Sampling method GB/T 222 GB/T 2975 The sampling position of each batch of steel plates, angle steels, slot steels and ball steels shall comply with the provisions of GB/T2975. 6. 2 T-shaped steels shall be cut at 1/3 of the width from one side. Round steels shall be cut at 1/3 of the radius from the outside. Acceptance rules 7.1 The acceptance of steel products shall be carried out by the technical supervision department of the party. Test method
GB/T223
.GB/T228
GB/T 232
GR 229
GB/T 22S
GB 712—2000
2 Steels shall be made from the same furnace number, same specification (model), same rolling system, and same heat treatment system. The weight of each batch shall not exceed 50t.
If controlled rolling is allowed to replace normalized steels, the weight of each batch shall not exceed 25t. The batch size for impact test shall comply with the quantity specified in the brackets of Table 4 and Table 5. 7.3 If the impact strength of the Charpy V-notch low-temperature impact test is lower than the average value specified in Table 6, no more than 2 samples will be lower than the average value, and no more than 1 sample will be lower than 70% of the average value. A group of three samples can be taken from the same steel or the same sample for testing. The average value of the two groups of 6 samples shall not be lower than the specified value. Two samples are allowed to be lower than the specified value, and only one sample is allowed to be lower than 70% of the specified value.
7.4 The re-inspection of other items shall comply with the provisions of GB/T247 and GB/T2101. 8 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel plates and types shall comply with the relevant provisions of GB/T247 and GB/T2101.1 The inspection items, sampling quantity, sampling method and test method of each batch of steel products shall comply with the provisions of Table 9. Table 9 Inspection items Chemical analysis Charpy (V-notch), impact Low manganese impact Item Sample quantity (for each batch) Sampling method GB/T 222 GB/T 2975 The sampling position of each batch of steel plates, angle steels, slot steels and ball steels shall comply with the provisions of GB/T2975. 6. 2 T-shaped steels shall be cut at 1/3 of the width from one side. Round steels shall be cut at 1/3 of the radius from the outside. Acceptance rules 7.1 The acceptance of steel products shall be carried out by the technical supervision department of the party. Test method
GB/T223
.GB/T228
GB/T 232
GR 229
GB/T 22S
GB 712—2000
2 Steels shall be made from the same furnace number, same specification (model), same rolling system, and same heat treatment system. The weight of each batch shall not exceed 50t.
If controlled rolling is allowed to replace normalized steels, the weight of each batch shall not exceed 25t. The batch size for impact test shall comply with the quantity specified in the brackets of Table 4 and Table 5. 7.3 If the impact strength of the Charpy V-notch low-temperature impact test is lower than the average value specified in Table 6, no more than 2 samples will be lower than the average value, and no more than 1 sample will be lower than 70% of the average value. A group of three samples can be taken from the same steel or the same sample for testing. The average value of the two groups of 6 samples shall not be lower than the specified value. Two samples are allowed to be lower than the specified value, and only one sample is allowed to be lower than 70% of the specified value.
7.4 The re-inspection of other items shall comply with the provisions of GB/T247 and GB/T2101. 8 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel plates and types shall comply with the relevant provisions of GB/T247 and GB/T2101.
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