This standard specifies the classification, code, size, shape, weight and allowable deviation, technical requirements, test methods, inspection rules, marking and quality certificate of steel for railway locomotive and vehicle axles. This standard is applicable to the manufacture of high-quality carbon structural steel square steel and round steel for railway locomotive and vehicle axles. GB 5068-1999 Railway locomotive and vehicle axle steel GB5068-1999 Standard download decompression password: www.bzxz.net

GB5068-1999
This standard adopts the Russian national standard IOCT4728-1996 "1520mm gauge railway locomotive and vehicle axle steel, technical conditions" to revise GB50681985 "railway locomotive and vehicle axle steel". This revision of this standard has been modified in the following aspects: The name of the standard has been changed to "railway locomotive and vehicle axle steel". - Added four specifications of square steel 230mm×230mm and round steel 230mm, 40mm.270mm: cancelled the square steel 196 mmX196 mm specification.
- Added two grades, JZ50 and LZ50. Reduced the phosphorus and sulfur content in the chemical composition, and increased the requirements for acid-soluble aluminum in steel. - Added the provisions for factory compression ratio and grain size grade, stipulated that axle steel should be vacuum degassed or slowly cooled, and adjusted the level of non-metallic inclusions.
Added Appendix A. wwW.bzxz.Net
From the date of implementation of this standard, it replaces GB5068-1985 "Axle steel for railway locomotives and vehicles". Appendix A of this standard is the appendix of the standard.
This standard is proposed by the State Metallurgical Industry Bureau. This standard is under the jurisdiction of the National Steel Standardization Technical Committee. The drafting units of this standard: Anshan Iron and Steel Group Corporation, Panzhihua Iron and Steel (Group) Corporation. The main drafters of this standard are Liu Xuyuan, Tong Changfu, Nie Caigong, Liu Hongxun and He Qingzhi. This standard was first issued in April 1985.
1 Scope
National Standard of the People's Republic of China
Axles steel for railway locomotive and wagons
Axles steel for railway locomotive and wagonsGB 5068— 1999
Replaces GB5068—1985
This standard specifies the classification, code, size, shape, weight and allowable deviation, technical requirements, test methods, inspection rules, marking and quality certificate for axles of railway locomotives and wagons. This standard is applicable to the manufacture of high-quality carbon structural steel square steel and round steel (hereinafter referred to as steel) for axles of railway locomotives and wagons. 2 References
\The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. The versions shown are valid at the time of publication of this standard. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest version of the following standards. GB/T222—1984 Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished products GB/T223.5—1997 Chemical analysis methods for steel and alloys - Reduced molybdenum silicate photometric method for determination of acid-soluble silicon content GB/T 223.12—1991 Chemical analysis methods for steel and alloys - Sodium carbonate separation-diphenylcarbazide photometric method for determination of chromium content GB/T 223.19—1989 GB/T223.24—1994 GB/T223.62—1988 GB/T 223.63—1988 GB/T 223.67—1989 GB/T 223. 69-1997
Methods for Chemical Analysis of Iron and Steel and Alloy
Determination of Copper Content by Neocuproine-Chloroform Extraction Spectrophotometric Methods for Chemical Analysis of Iron and Steel and Alloys Extraction Separation-Diacetyl Spectrophotometric Method for Nickel Content by Extraction Separation-Diacetyl Spectrophotometric Method for Chemical Analysis of Iron and Steel and Alloys
Determination of Phosphorus Content by Butyl Acetate Extraction Spectrophotometric Method
Methods for Chemical Analysis of Iron and Steel and Alloys
Determination of Manganese Content by Sodium (Potassium) Periodate Spectrophotometric Method
Methods for Chemical Analysis of Iron and Steel and Alloys
Determination of Sulfur Content by Reduction Distillation-Methylene Blue Spectrophotometric Method Determination of Carbon Content by Gas Volumetric Method after Combustion in Tube Furnace
Methods for Chemical Analysis of Iron and Steel and Alloys
GB/T226—1991 Acid Etching Method for Macrostructure and Defects of SteelGB/T228—1987
GB/T 229—1994
Metal tensile test method
Metal Charpy notch impact test method
GB/T1979—1980 Structural steel macrostructure defect rating diagram General provisions for acceptance, packaging, marking and quality certificate of structural steel GB/T 2101—1989
GB/T 6397—19863
Gold chip tensile test specimen
GB/T 10561—1989
Microscopic evaluation method for non-metallic inclusions in steel YB/T5148—1993 Method for determination of average grain size of metals 3 Classification, code
3.1 Classification
Steel materials are divided into two categories according to their use: railway locomotive axles and vehicle axles (including coal and water vehicles). 3.2 Code
Steel code for locomotive axles: JZ (JZ is the Chinese phonetic prefix for locomotive axles); Steel code for vehicle axles: LZ (LZ is the Chinese phonetic prefix for vehicle axles). Approved by the State Administration of Quality and Technical Supervision on November 23, 1999 and implemented on August 1, 2000
4 Dimensions, shape, weight and allowable deviations
4.1 Dimensions and allowable deviations
GB 5068—1999
4.1.1 The cross-sectional dimensions and allowable deviations of square steel shall comply with the provisions of Table 1. 4.1.2 The dimensions and allowable deviations of round steel shall comply with the provisions of Table 2. 4.1.3 Other specifications of axle steel may be supplied upon agreement between the supplier and the buyer and specified in the contract. 4.1.4 The fixed length or multiple length of steel shall be determined by negotiation between the supplier and the buyer and specified in the contract. The allowable deviation of its fixed length or total length of multiple lengths is +80
4.2 Appearance
4.2.1 The corners of the square steel section should be arc-shaped, and the radius of the fillet should be 0.1~~0.2 times the nominal side length. After negotiation between the supply and demand parties and indication in the contract, square steel for axles with other fillet radii can be supplied. Table 1
Steel for vehicle axles
Steel for locomotive axles
Copper for vehicle and locomotive axles
Square steel section size
Height×width
220×220
230×230
240×240
250×250
280×280
300×300
320×320
350×350
Round steel diameter
Allowable deviation
Allowable deviation
4.2.2 Concavity of square steel surface: For square steel with section size less than 240mm×240mm, the convexity of each surface shall not be greater than the height allowable deviation value in Table 1: For square steel with section size not less than 240mm×240mm, the convexity of each surface shall not be greater than 4.5mm. 4.2.3 Non-roundness of round steel For round steel with diameter less than 270mm, the non-roundness shall not be greater than 4.0mm For round steel with diameter not less than 270mm, the non-roundness shall not be less than 4.5mm.
4.2.4 When shearing, the flattening value of the end of the square steel shall not be greater than 25% of the side length of the square steel section. 4.3 Weight
4.3.1 Steel shall be delivered according to actual weight or theoretical weight. When delivered by theoretical weight, the weight is calculated as follows: Square steel: G = 0.981 × 10-° × (25 + L) a\p; Round steel: G = yuan R2 × 10-× (25 + L) p
-The weight of steel for each axle.kg1
o——Steel density, 7 850 kg/m;
a—Nominal side length of square steel section, mm;
GB 5068-1999
1Fixed length (or multiple length total length), or non-fixed length minus 25mn; R-Radius of round steel, mm;
Pi, 3.14
Consider the fillet radius of square steel and the coefficient obtained by conversion. 4. 3.2 The theoretical weight of steel shall comply with the provisions of Table 3. Table 3
Cross-sectional dimensions, mm
220X220
230×230
240×240
250X250
280×280
300X300
5 Technical requirements
5.1 Chemical composition
Theoretical weight, kg/m
Cutting dimensions, mm
320X320
350×350
5.1.1 The chemical composition (melting analysis) of axle steel shall comply with the provisions of Table 4. 5.1.2 The content of acid-soluble aluminum Als in steel shall not be less than 0.015%. 5.1.3 The allowable deviation of the chemical composition of the finished axle steel shall comply with the provisions of GB/T222. Theoretical weight, kg/m
5.1.4 Axle steels of other grades and chemical compositions may be supplied upon agreement between the supplier and the buyer and specified in the contract. 5.2 Refining method
5.2.1 Axle steel should be smelted by converter and electric furnace. 5.2.2 Axle steel should be vacuum degassed, and the hydrogen content of liquid steel should not be greater than 2.5×10-5; the oxygen content should not be greater than 30×10-. Axle steel that has not been vacuum treated must be slowly cooled. Table 4
Chemical composition, %
5.3 Delivery status
0.37~~0.45
0. 40~-0. 48
0. 47~~0.57
Steel is delivered in hot rolled state.
5.4 Mechanical properties
0.50~0.80
0. 55~-0. 85
0. 60~-0.90
0.17~0.37
0.17~0.37
Not more than
The mechanical properties of steel measured by the test specimens made of the normalized sample shall comply with the provisions of Table 5 and Table 6. 5.5 Macrostructure
5.5.1 There shall be no visible residual shrinkage cavities, white spots, delamination, cracks, bubbles and inclusions on the transverse acid leaching macro specimen of steel. The depth of subcutaneous inclusions and subcutaneous bubbles shall comply with the provisions of Table 7. Brand
Tensile strength
≥550~570
>570~600
2570590
>590~620
220×220
230×230
240×240
250X250
280×280
300×300
320×320
350×350
Elongation
Service point
GB 5068-—1999
4 Average value of samples
Tensile strength
Impact energy Au (normal temperature)
Not less than
Elongation yield
Depth of subcutaneous inclusions and subcutaneous bubbles
5.5.2 The acid immersion macrostructure level of steel shall comply with the requirements of Table 8. Table 8
250×250
p230.4240
>250×250
5.6 Non-metallic inclusions
General looseness
Central looseness
Minimum value of sample
Sectional reduction rate 5
Not more than
Ingot-shaped segregation
Not more than
Point segregation
The inspection of non-metallic inclusions in steel shall be evaluated according to the A method in GB/T10561-1989 and the JK standard rating chart. The inspection shall comply with the following provisions:
When evaluating inclusions according to GB/T 10561, the evaluation results of Class A or Class C inclusions (coarse or fine) shall be used as the inspection results of "sulfide", and the more serious one shall be used for judgment; the evaluation results of Class B inclusions (coarse or fine) shall be used as the inspection results of "oxide", and the more serious one shall be used for judgment.
GB 5068 -- 1999
For Class A and Class C inclusions appearing in the same field of view, they should be evaluated together, and the corresponding rating picture should be selected based on the dominant inclusion. Class B inclusions and Class D inclusions similar in size to Class B inclusions appearing in the same field of view should also be evaluated together and reported as Class B inclusions:
When the size of inclusions in the field of view is between the coarse and fine series, they should be evaluated according to the closest series. The inspection results of non-metallic inclusions in the axle steel should meet the following requirements: Class A or Class C non-metallic inclusions in axle steel should not exceed 3.0 level, and Class B non-metallic inclusions should not exceed 2.5 Grade. 5.7 Grain size
The grain size of the normalized test block of JZ50.LZ50 steel shall not be less than grade 5.0. 5.8 Surface quality
5.8.1 The end face of the steel shall not have pores, inclusions and delamination. 5.8.2 The surface of the steel shall not have scars, inclusions, folds, bubble streaks and cracks. If there are any above defects, they shall be removed. Indentations with a depth of no more than 2 mm and pits caused by the shedding of ammoniated iron sheets do not need to be removed. The height or depth of the bumps and concavities caused by roll marks and welding points shall not be greater than 5mm. 5.8.3 The cleaning of steel shall comply with the following provisions. 1) Cleaning shall be carried out along the length of the steel, and its edges shall have a smooth transition; the width-to-depth ratio of the cleaning shall not be less than 6:1. The cleaning depth (calculated from the actual size) shall comply with the provisions of Table 9. b) The cross-sectional size of a 220mm×220mm square steel after cleaning shall not be less than 206mm. The minimum cross-sectional size after local cleaning shall not be less than 204 mm×204mm, the cleaning length should not exceed 300mm; c) If the cleaning depth is greater than the minimum cross-sectional size by 3mm, it should not exceed 4 places on the same cross-section (except 220mm×220mm).
Square steel with size
≤240×240-$230, 240
250×250300×300 square steel, $270>300×300 square steel
5.9 Rolling compression ratio
The rolling compression ratio of steel should not be less than 6.1. 5. 10 Special requirements
Cleaning depth
Not more than
According to the requirements of the purchaser, the supply and demand parties shall negotiate and determine, and indicate in the contract, other items of inspection may be carried out. 6 Test methods
The sampling quantity, sampling location and test method of each batch of steel shall comply with the provisions of Table 10. Table 10
Inspection items
Chemical composition
Tensile test
Impact test
Grain size
Non-metallic inclusions
Macrostructure
Sampling quantity
1 per can
Sampling method and location
GB/T222
The head of any steel with \A\, the sample
defective length shall not be less than 300 mm.
The method of cutting test blocks from the sample shall be in accordance with
Appendix A (Appendix to the standard)
Test methods
GB/T223
GB/T 228.GB/T 6397
GB/T 229
YR/T 5148
GB/T10561
GB/T226
Caliper, ruler
Inspection rules
7.1 Inspection and acceptance
GB 5068- 1999
The inspection and acceptance of steel products shall be carried out by the supplier's technical supervision department. The purchaser has the right to conduct acceptance according to this standard. 7.2 Batch rules
Steel products shall be accepted in batches. Each batch shall consist of steel products of the same grade, furnace number and specification. 7.3 Re-test and judgment rules
If one of the test results does not meet the requirements of this standard, the steel shall be picked out. In addition, two samples of the same length shall be taken from the heads of any two copper materials with the letter "A" in the batch to re-test the unqualified items (except white spots). The furnace number and the letter "A" must be marked on the samples. If even one of the re-test results (including any index required by the test) is unqualified, all the steels with the letter "A" in the batch shall not be accepted. At this time, a sample can be cut from the other end or the head of the B end of any two steels with the letter "A" for testing. When all the test results are qualified, the steels except the "A" section are qualified; if one of the samples is unqualified, the entire batch shall not be accepted. 8 Marking and Quality Certificate
8.1 Marking
8.1.1 The end face of all steel products at the head of the ingot must be clearly marked with "A". When one ingot is used to roll more than two steel products, the end face of the second steel product at the head of the ingot shall be marked with "B". 8.1.2 The steel grade, furnace (tank) number and A and B section numbers shall be marked on the surface of each steel product. 8.2 Quality certificate
The quality certificate of steel shall comply with the provisions of GB/T2101, C 5068-1999
Appendix A
(Standard Appendix)
Test block size and cutting position for mechanical properties, grain size and non-metallic inclusions The test blocks used for mechanical properties testing are cut from the sample, and the test block size shall comply with the provisions of Table A1; the test block cutting position is shown in Figure A1a, Figure A1b and Figure A2. The grain size test sample is cut from the residual head of the tensile test sample. The non-metallic inclusion test sample is cut from the longitudinal center plane of the residual head of the tensile test sample.
Cross-sectional dimensions of steel for axles
220×220
>220×220
230~-270
Test block dimensions
100×100
140×140
Quarter-circular surface
1—Two of the four impact toughness specimens; 2—Tensile test specimens 13—Automatic cutting line diagram A1
1—Tensile specimen ($20mm), high-power mixed specimen, 2—Impact specimen <20mm); 3—Heat treatment test block cutting line diagram A2 Schematic diagram of round steel sampling
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.