Some standard content:
National Standard of the People's Republic of China
Cold rolled stainless steel strips For springs
Cold rolled stainless steel strips For springs1 Subject content and scope of application
GB/T 4231--93
Replaces H 4231-84
This standard specifies the size, appearance, technical requirements, inspection methods, inspection rules, packaging, marking and quality certificate of cold rolled stainless steel strips for springs.
This standard applies to cold rolled stainless steel strips for leaf springs and coils with a thickness not exceeding 1.0 mm and a width not exceeding 10.25 mm (hereinafter referred to as cold rolled stainless steel strips).
2 Referenced standards
(G-3 222
GB 223
61 228
GR 247
Sampling method for chemical analysis of steel and allowable deviation of chemical composition of products Chemical analysis methods for steel and alloys
Metal drawing test method
Metal bending test method
General specification for inspection, packaging, marking and quality certificate of steel poles and steel strips GR 2975
GB 3076
(13 4239
GB 4340
G 6397
3 Classification and code
Steel mechanical and process performance test sampling regulations Metal sheet (Bi) tensile test method
Stainless steel cold-rolled strip
Metal hardness test method
Metal lathe test specimen
3.1 Classification by manufacturing accuracy
Thickness ordinary steel strip
Original thickness high precision steel
3.2 Classification by film degree
Low-density steel strip
Carbon steel strip
Cold-rolled steel strip
Hold-rolled tree strip
3.3 Classification by edge state
Cut steel strip
Non-cut steel strip
Approved by the State Administration of Technical Supervision in 1993-0217
1993-10-01 Field
Categories and grades
GB/T231
Steel strips are divided into three categories according to metallographic structure, with a total of four grades. The categories and grades are listed in Table 1. Table 1 Categories and grades
Austenite
Martensite
Precipitation hardening
Note: According to the requirements of the supplier and after consultation with the supplier, other grades other than those in Table 1 can be provided. 5 Size and shape
1Cr17Ni7.0Cr18Nis
OC17Ni7Al
5.7 The recommended hardness of steel strips is 0.10, 0.12, 0.15, 0.20, 0.25, 0.28, G, 30, 0.35, 0.46, 0.45, 0.50, 0.55, 0.60, t. 70,0.80,0.90,1.00,1.10,1.20,1.40,1.60 mm.5.2 The thickness of the steel strip is allowed to be distorted as specified in Table 2. According to the requirements of the piece (specified in the contract), the allowable deviation of the steel strip can be limited to the positive or negative value. However, the tolerance at this time should be equal to the tolerance value specified in Table 2. 3 The width of the steel strip push float is 10,13,16,20.25.32,40.50,63.80,100,125,160200,250mm. 5.3
Table 2 Thickness Allowable Deviation
0.10--0.15
0, 15 ~-0. 25
>0. 25 -~-0. 45
: 0. 15 ~- 0, 65
-0. 65-- 0. 90
--. 9-- 1. 20
1. 20--1. 50
-1. 50-- 1, 60
—0. 032
二0. 04
Universal precision
2150-250
Advanced precision
280-~250
GB/T4231: 93
5.4The width allowable deviation of the steel strip shall be in accordance with Table 3. According to the requirements of the purchaser (specified in the contract), the width allowable deviation of the steel strip can be limited to the positive or negative side. However, the tolerance value at this time shall be equal to the tolerance value specified in Table 3. Table 3 Width allowable deviation
Steel strip thickness
-0. 53-- 1. 05
-1. 03-- 1. 60
Steel strip width
80--150
150----.250
5.5The maximum value of the blade bending of the steel strip shall be in accordance with Table 4. The value of 1+ is applicable to the ratio of width to height greater than 10. Maximum allowable value of sickle bending
Steel strip width, t11n
10~---20
20--:10
:0--80
Maximum allowable value per meter, ain/m
When the steel strip width is not more than 10OmmH, the maximum unevenness S perpendicular to the rolling direction shall not exceed the value calculated by the following formula: 5.6
s(mm) -
6 Technical requirements
6.1 Brand and chemical composition
×.2 (calculated and estimated to one decimal place)55
6.1.1 The chemical composition of steel (melt trace analysis) shall comply with the provisions of GB4239. 6.1.2 When the chemical composition analysis of the finished product is carried out (the purchaser's inspection or the supplier's inspection according to the purchaser's requirements), the allowable difference shall comply with the short definition of Table 3 in (222). For the elements or chemical composition regulations that are not applicable to Table 3, they shall be arranged in accordance with the agreement between the supply and demand parties. 6. 2 Delivery state
The steel strip is delivered in soft state and cold worked state. According to the degree of cold work hardening, it is divided into TDY, RY, Y and TY states. 3Ct13 steel strip is delivered in annealed state, and r17Ni7A1 is delivered in solution treated state. 6.3 Mechanical properties and process properties
6.3.1 The hardness and bending properties of the steel strip shall be as specified in Table 5. Grade
1Cr17Ni7
oCr19Ni9
OCr17Ni7A!
Delivery state
Usually: t Set of bending diameters One steel thickness
GB/T 4231-93
Table 5 Mechanical properties and process properties of steel strip
Cold rolled, solid bath treated or annealed state
2≥490
Bending test
V-type bending
d - 5a
W-type bending
uz20.5mmwww.bzxz.net
a0. 5 tnm Appendix
Precipitation hardening treatment status
Heat treatment
Solution+565 aging
Shang+51CC aging
1Y+475 aging
BY-1-475r: aging
Y- 475 C aging
When the thickness of the steel strip is less than 0.40mm, the tensile strength value can be used instead of the hardness value. The strength value is as specified in Table 6. Table 6 Service strength, tensile strength and elongation Cold wheel or solid test state
1Cr17Ni7
Delivery state
Service strength
Tensile strength
2=1 570
Elongation
Precipitation hardening treatment
Heat treatment
Urinary strength Tensile strength
(Cr1yNi3
(C-17Ni7A)
Delivery condition
Urinary strength
GB/T 4231-—93
Continued Table 6
Cold rolling or solidification state
Tensile strength
:1 180
-1 420
Changxin
Precipitation hardening treatment state
Sleeping strength Tensile strength
Heat treatment
Solidification +565℃ aging
Weekly melting +510℃ aging
Y+475 aging
PY! 475 aging
Y-475C aging
=1 231
21 727:
6.3.1.2 The longitudinal direction of the cold bending test specimen shall be perpendicular to the square of the steel strip. For the specimens subjected to the cold bending test, the outer surface of the bending part shall not have cracks
The bending angle of the cold bending test of 5 is 90. According to the requirements of the purchaser, W-type bending can be used instead of V-type bending. W-type bending 6. 3. 1.3
Bending test is shown in Figure 1.
Unit: mm
Above 20mm
For steel strips with a width less than 30mm and a thickness greater than 1.m, V-type side bend test shall be carried out: For steel strips with a width less than 30mm and a thickness greater than .80mm, W-type bending test shall not be carried out. 6.3.2 According to the requirements of the purchaser, the steel strip with a thickness of not less than 0.30mm shall be subjected to tensile test instead of the hardness and bending test specified in Table 5. The strength, tensile strength and elongation of the steel strip shall be in accordance with the provisions of Table 6. 6-3.2.1 The precipitation hardening heat treatment process of Cr17Ni7A1 is as follows: When the steel strip is in the solution treatment state, it shall be aged at 565℃ in any of the following ways: keep it at 760±15℃ for 90min, then cool it to below 15℃ within 1h and keep it at 565±10℃ for 30min, and then keep it at 565±10℃ for 60min.
Ageing at 510℃, keep at 955+10℃ for 10min, cool to room temperature, keep at 73±6℃ for 8h within 24h, keep at 510±10℃ for 20min and then air cool.
GB/1 4231--93
When the steel strip is delivered in the cold-work hardened state of DY, BY, Y, the following heat treatment process shall be applied: cold rolling at different degrees, keep at 475+b.
10℃ for 1h and then air cool.
6.4 Surface quality
The steel strip shall not have defects that are harmful to use. In the absence of special requirements, individual slight scratches, indentations, concave surfaces, marks and pits are generally allowed on the surface, and their depth or height shall not exceed the thickness tolerance of the steel strip. 7 Test method
7.1 When measuring the camber of the steel strip, place the inspected part of the steel strip flat on the platform, use a 1㎡ long ruler to touch the concave side of the steel strip, and measure the maximum distance between the steel strip and the ruler.
7.2 When measuring the unevenness S of the steel strip, the cut steel strip of appropriate length should be placed on the platform as shown in Figure 2, and then the distance S between the center of the steel strip and the steel block should be measured with a thickness gauge or wire gauge. When the width of the steel strip is less than 7mm, the length of the steel block L is 75mm. When the width is not less than 70mm, the length of the steel block is
unit, mm
7.3 The thickness of the steel strip is measured at the center of the width of the steel strip. For the width of 30 to 250mm, the cut edge steel strip should be measured at a distance of 5mm from the edge, and the uncut steel strip should be measured at a distance of 10mm from the edge.
7.4 Each test item H and the number of samples, sampling locations and test methods shall comply with the provisions of Table 7. Table 7
Test items
Chemical analysis
Sample number
Special provisions
Test method
GB 223 Method not specified
Agreed by both parties
Test top door
Tensile test
Hardness test
Flexibility test
8 Inspection rules
8.1 Inspection and verification
Test basis
GB/T 4231 93
Continued Table 7
Huancheng filter
GBE357
Or sample
Rolling direction Take the rod
The sample is cut from the tensile bending
The steel strip is sent to the supplier's technical supervision department for standardization and acceptance. 8.2 Batch rules
Test supervision method
GB3076
GB4310
G5: 232
Use G28 1%
-5.6·VF standard properties about
Sample: Determine the tensile strength
, the strain increase of the selected parallel parts
is required to be maintained at 1m~80% per
minute: the test
temperature is 5 The test temperature is 21°C and the test temperature is 20°C. The W-type bend is measured by the inspection worker according to the drawing. The steel strip is produced and accepted by the inspection worker in batches. Each batch of steel strips should be made of the same batch number, the same furnace number, the same specification, the same heat treatment furnace and the same delivery status. 8-3 Re-inspection and determination of summer heat treatment of steel strips The inspection and judgment rules shall comply with the provisions of GB21. 9 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel strips shall comply with the provisions of GB2. Additional remarks:
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was issued by the Ministry of Metallurgical Industry Information Standard Research Institute, Shanghai No. 9 Steel Supply Factory, and the Ministry of Metallurgical Industry Information Standard Research Institute. The main applicants of this standard are South Korea, France, and Shenyang. This standard is the level mark GB/1231:93YThe W-type bending machine is bent according to the drawing. The steel strip is inspected and accepted by the inspection personnel in batches. Each batch of steel strips shall be made of the same batch number, the same furnace number, the same specification, the same heat treatment furnace and the same delivery status. 8-3 Re-inspection and judgment regulations The inspection and judgment regulations of steel strips shall comply with the provisions of GB21. 9 Packaging, marking and quality certificate The packaging, marking and quality certificate of steel strips shall comply with the provisions of GB2. Additional remarks: This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was issued by the Information Standard Research Institute of the Ministry of Metallurgical Industry and the Shanghai No. 9 Steel Supply Factory, the Information Standard Research Institute of the Ministry of Metallurgical Industry. This standard is mainly used by Vietnamese, Korean, French, and Chinese people. This standard is the level mark GB/1231:93YThe W-type bending machine is bent according to the drawing. The steel strip is inspected and accepted by the inspection personnel in batches. Each batch of steel strips shall be made of the same batch number, the same furnace number, the same specification, the same heat treatment furnace and the same delivery status. 8-3 Re-inspection and judgment regulations The inspection and judgment regulations of steel strips shall comply with the provisions of GB21. 9 Packaging, marking and quality certificate The packaging, marking and quality certificate of steel strips shall comply with the provisions of GB2. Additional remarks: This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was issued by the Information Standard Research Institute of the Ministry of Metallurgical Industry and the Shanghai No. 9 Steel Supply Factory, the Information Standard Research Institute of the Ministry of Metallurgical Industry. This standard is mainly used by Vietnamese, Korean, French, and Chinese people. This standard is the level mark GB/1231:93Y
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