Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 3203-1982 Specification for Carburizing Steels of Bearings.
The following technical changes have been made with respect to GB/T 3203-1982:
——Bright round steel is added and "steel billet" is cancelled (see Chapter 1);
——“Normative References" is added (see Chapter 2)
——"Classification and Designation" is added (see Chapter 3);
——"Order Contents" is added (see Chapter 4);
——Dimension, shape and tolerance are modified (see Chapter 5; Chapter 1 in Edition 1982);
——Designation G23Cr2Ni2Si1Mo and relevant technical requirements are added (see 6.1.1, 6.5, 6.6 and 6.8);
——Requirements for nickel content in G20CrMo steel as well as molybdenum content in G20Cr2Ni4 steel are added (see Table 4; Table 2 in Edition 1982);
——Requirements for silicon content, manganese content and chromium content in G20CrNiMo and G20CrNi2Mo steels are modified (see Table 4; Table 2 in Edition 1982);
——Requirements for phosphorus content and sulfur content are stricter, and requirements for aluminium content, titanium content, calcium content, oxygen content and hydrogen content are added (see Table 5; Table 2 in Edition 1982);
——Smelting process with open-hearth furnace is deleted (see 2.2 in Edition 1982);
——Mechanical property is modified as the agreement requirement; mechanical property index of G20CrMo steel is added, and mechanical property index of G20CrNiMo steel is modified (see 6.5; 2.4 in Edition 1982);
——The hardenability index of G20CrMo steel is added, and the lower limit for the hardness of G20CrNi2Mo 9mm away from the end is increased (see Table 9; Table 5 in Edition 1982);
——The qualified grade of macrostructure defect of high-grade fine steel is stricter (see Table 10; Table 6 in Edition 1982);
——Inspection standard, sampling method and sampling quantity of non-metallic inclusion are modified, and the rating requirements of titanium nitride are added (see 6.9; 2.7 in Edition 1982);
——Requirements for microstructure are modified as the requirements in the agreement (see 6.11; 2.9 in Edition 1982);
——Decarburized layer detection is added (see 6.12);
——Ultrasonic testing requirements are modified (see 6.14; 2.11 in Edition 1982);
——Reinspection and judgment rules are revised (see Table 8.4; 4.3 in Edition 1982);
——Packaging, marking and quality certificate are modified (see Chapter 9; Chapter 5 in Edition 1982);
This standard was proposed by China Iron and Steel Association.
This standard is under the jurisdiction of the National Technical Committee on Iron and Steel of Standardization Administration of China (SAC/TC 183).
The previous edition of this standard is as follows:
——GB/T 3203-1982.
Carburizing Steels for Bearing
1 Scope
This standard specifies provisions for carburizing steels for bearing, including classification and code, order contents, dimension, shape, technical requirements, test methods, inspection rules, packaging, marking and quality certificate.
It is applicable to hot-rolled, hot-forged or cold-drawn carburizing steels for bearing as well as bright round steel (hereinafter referred to as steels) used for manufacturing bearing ring and rolling element.
Subject to the negotiation between the supplier and the demander, and with the specific requirements indicated in the contract, steels of other designations and dimensions may also be supplied.
2 Normative Reference
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 223.5 Steel and Iron - Determination of Acid-soluble Silicon and Total Silicon Content - Reduced Molybdosilicate Spectrophotometric Method
GB/T 223.9 Iron, Steel and Alloy - Determination of Aluminium Content - Chrom Azurol S Photometric Method
GB/T 223.11 Iron Steel and Alloy - Determination of Chromium Content - Visual Titration or Potentiometric Titration Method
GB/T 223.19 Methods for Chemical Analysis of Iron, Steel and Alloy: the Neocuproine-chloroform Extraction Photometric Method for the Determination of Copper Content
GB/T 223.23 Iron Steel and Alloy - Determination of Nickel Content - the Dimethylglyoxime Spectrophotometric Method
GB/T 223.26 Iron Steel and Alloy - Determination of Copper Content - the Thiocyanate Spectrophotometric Method
GB/T 223.59 Iron Steel and Alloy - Determination of Phosphorus Content - Bismuth Phosphomolybdate Blue Spectrophotometric Method and Antimony Phosphomolybdate Blue Spectrophotometric Method
GB/T 223.60 Methods for Chemical Analysis of Iron, Steel and Alloy - the Perchloric Acid Dehydration Gravimetric Method for the Determination of Silicon Content
GB/T 223.63 Methods for Chemical Analysis of Iron, Steel and Alloy - the Sodium (Potassium) Periodate Photometric Method for the Determination of Manganese Content
GB/T 223.68 Methods for Chemical Analysis of Iron, Steel and Alloy - the Potassium Iodate Titration Method after Combustion in the Pipe Furnace for the Determination of Sulfur Content
GB/T 223.69 Iron Steel and Alloy - Determination of Carbon Contents - Gas-volumetric Method after Combustion in the Pipe Furnace
GB/T 223.77 Methods for Chemical Analysis of Iron, Steel and Alloy - the Flame Atomic Absorption Spectrometric Method for the Determination of Calcium Content
GB/T 223.82 Steel and iron - Determination of Hydrogen Content - Inert Gas Impulse Fusion Heat Conductivity Method
GB/T 223.84 Steel and Alloy - Determination of Titanium Content - Diantipyrylmethane Spectrophotometric Method
GB/T 224-2008 Determination of Depth of Decarburization of Steel
GB/T 225 Steel - Hardenability Test by End Quenching (Jominy Test)
GB/T 226 Etch Test for Macrostructure and Defect of Steels
GB/T 228.1 Metallic Materials - Tensile Testing - Part 1: Method of Test at Room Temperature
GB/T 229 Metallic Materials - Charpy Pendulum Impact Test Method
GB/T 231.1 Metallic Materials - Brinell Hardness Test - Part 1: Test Method
GB/T 702-2008 Hot-rolled Round and Square Steel Bars - Dimension, Shape, Weight and Tolerance
GB/T 905-1994 Dimension, Shape, Weight and Tolerance for Cold-drawn Round, Square and Hexagonal Steels
GB/T 908-2008 Forged Bars - Dimension, Shape, Weight and Tolerance
GB/T 1979 Standard Diagrams for Macrostructure and Defect of Structural Steels
GB/T 2101 General Requirement of Acceptance, Packaging, Marking and Certification for Section Steel
GB/T 2975 Steel and Steel Products - Location and Preparation of Test Pieces for Mechanical Testing
GB/T 3207-2008 Bright Steel
GB/T 4162 Forged and Rolled Steel Bars - Method for Ultrasonic Examination
GB/T 4336 Standard Test Method for Spark Discharge Atomic Emission Spectrometric Analysis of Carbon and Low-alloy Steel (Routine Method)
GB/T 6394-2002 Metal-methods for estimating the average grain size
GB/T 10561-2005 Steel - Determination of Content of Nonmetallic Inclusions - Micrographic Method Using Standards Diagrams
GB/T 11261 Steel and Iron - Determination of Oxygen Content - the Pulse Heating Inert Gas Fusion - Infrared Absorption Method
GB/T 15711 Steel Products - Method for Etch Test of Tower Sample
GB/T 20066 Steel and Iron - Sampling and Preparation of Samples for the Determination of Chemical Composition
GB/T 20123 Steel and Iron - Determination of Total Carbon and Sulfur Content Infrared Absorption Method after Combustion in an Induction Furnace (Routine Method)
YB/T 4307 Iron Steel and Alloy - Determination of Oxygen, Nitrogen and Hydrogen Contents - Pulse Heating Inert Gas Fusion - Time of Flight Mass Spectrum (Routine Method)
3 Classification and Code
3.1 According to metallurgical quality, steels are classified into:
a) fine steel
b) high-grade fine steel (designation followed by "A");
3.2 According to smelting process, steels are classified into:
a) vacuum-degassed steel;
b) electroslag remelting steel.
3.3 According to processing way, steels are classified into:
a) hot-forged (WHF) steel;
b) hot-rolled (WHR) steel
c) cold drawn (WCD) steel;
d) bright steel;
1) flayed steel (SF)
2) polished steel (SP).
3.4 According to the usage and processing purposes, steels are classified into:
a) steel for pressure work (UP);
b) steel for cut work (UC).
4 Order Contents
Order contract in accordance with this standard shall include the following information at least:
a) standard number;
b) designation;
c) dimension and accuracy;
d) weight and/or quantity;
e) smelting process (see 6.2);
f) delivery state (see 6.3);
g) metallurgical quality (see 6.2, 6.7~6.9);
h) applied processing method (see 6.13);
i) items or indexes that shall be indicated in the contract subjected to the negotiation by the supplier and the demander;
j) other special requirements.
5 Dimension, Shape and Weight
5.1 Dimension
5.1.1 Diameter and tolerance
The diameter and tolerance of steel shall be in accordance with those specified in Table 1.
Table 1 Diameter and Tolerance of Steel
Steel type Nominal diameter, mm, not greater than Tolerance
Hot-rolled round steel 310 Second group in Table 1 of GB/T 702-2008
Hot-forged round steel 400 First group in GB/T 908-2008
Cold-drawn round steel 60 Grade h11 a in GB/T 905-1994
Bright round steel 120 Grade 11(h11) a in Table 4 of GB/T 3207-2008
a Agreed by the supplier and the demander and being indicated in the contract, the steels may also be delivered according to other grades.
5.1.2 Length
5.1.2.1 The delivery length of steel shall meet those specified in Table 2.
Table 2 Length of Steel Dimensions in mm
Steel type Normal length a Whether delivered in short length is allowed
Hot-rolled round steel 3 000~12 000 Not allowed
Hot-forged round steel 2 000~6 000 Not allowed
Cold-drawn round steel 3 000~6 000 Short length steels with length not less than
2 000mm are allowed to be delivered, but the weight shall not exceed 10% total weight of this batch.
Bright round steel 4 000~7 000
a Agreed by the supplier and the demander and being indicated in the contract, steels of other length requirements may also be provided.
5.1.2.2 Steels shall be delivered by uniform length within the specified length range, and the length difference between the longest and shortest steels in each bundle shall not be larger than 1 000mm.
5.1.2.3 Steels may be delivered according to specified length or double length, their length shall be indicated in the contract and the tolerance is +50 0mm.
5.2 Shape
5.2.1 Curvature and ovality
The curvature and ovality of steels shall be in accordance with those specified in Table 3. As agreed by both the supplier and the demander and indicated in the contract, steels of other curvatures and ovalities may also be provided.
Foreword i 1 Scope 2 Normative References 3 Classification and Code 4 Order Contents 5 Dimensions, Shapes and Weights 6 Technical Requirements 7 Test Methods 8 Inspection Rules 9 Packaging, Marking and Quality Certificate
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 3203-1982 Specification for Carburizing Steels of Bearings.
The following technical changes have been made with respect to GB/T 3203-1982:
——Bright round steel is added and "steel billet" is cancelled (see Chapter 1);
——“Normative References" is added (see Chapter 2)
——"Classification and Designation" is added (see Chapter 3);
——"Order Contents" is added (see Chapter 4);
——Dimension, shape and tolerance are modified (see Chapter 5; Chapter 1 in Edition 1982);
——Designation G23Cr2Ni2Si1Mo and relevant technical requirements are added (see 6.1.1, 6.5, 6.6 and 6.8);
——Requirements for nickel content in G20CrMo steel as well as molybdenum content in G20Cr2Ni4 steel are added (see Table 4; Table 2 in Edition 1982);
——Requirements for silicon content, manganese content and chromium content in G20CrNiMo and G20CrNi2Mo steels are modified (see Table 4; Table 2 in Edition 1982);
——Requirements for phosphorus content and sulfur content are stricter, and requirements for aluminium content, titanium content, calcium content, oxygen content and hydrogen content are added (see Table 5; Table 2 in Edition 1982);
——Smelting process with open-hearth furnace is deleted (see 2.2 in Edition 1982);
——Mechanical property is modified as the agreement requirement; mechanical property index of G20CrMo steel is added, and mechanical property index of G20CrNiMo steel is modified (see 6.5; 2.4 in Edition 1982);
——The hardenability index of G20CrMo steel is added, and the lower limit for the hardness of G20CrNi2Mo 9mm away from the end is increased (see Table 9; Table 5 in Edition 1982);
——The qualified grade of macrostructure defect of high-grade fine steel is stricter (see Table 10; Table 6 in Edition 1982);
——Inspection standard, sampling method and sampling quantity of non-metallic inclusion are modified, and the rating requirements of titanium nitride are added (see 6.9; 2.7 in Edition 1982);
——Requirements for microstructure are modified as the requirements in the agreement (see 6.11; 2.9 in Edition 1982);
——Decarburized layer detection is added (see 6.12);
——Ultrasonic testing requirements are modified (see 6.14; 2.11 in Edition 1982);
——Reinspection and judgment rules are revised (see Table 8.4; 4.3 in Edition 1982);
——Packaging, marking and quality certificate are modified (see Chapter 9; Chapter 5 in Edition 1982);
This standard was proposed by China Iron and Steel Association.
This standard is under the jurisdiction of the National Technical Committee on Iron and Steel of Standardization Administration of China (SAC/TC 183).
The previous edition of this standard is as follows:
——GB/T 3203-1982.
Carburizing Steels for Bearing
1 Scope
This standard specifies provisions for carburizing steels for bearing, including classification and code, order contents, dimension, shape, technical requirements, test methods, inspection rules, packaging, marking and quality certificate.
It is applicable to hot-rolled, hot-forged or cold-drawn carburizing steels for bearing as well as bright round steel (hereinafter referred to as steels) used for manufacturing bearing ring and rolling element.
Subject to the negotiation between the supplier and the demander, and with the specific requirements indicated in the contract, steels of other designations and dimensions may also be supplied.
2 Normative Reference
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 223.5 Steel and Iron - Determination of Acid-soluble Silicon and Total Silicon Content - Reduced Molybdosilicate Spectrophotometric Method
GB/T 223.9 Iron, Steel and Alloy - Determination of Aluminium Content - Chrom Azurol S Photometric Method
GB/T 223.11 Iron Steel and Alloy - Determination of Chromium Content - Visual Titration or Potentiometric Titration Method
GB/T 223.19 Methods for Chemical Analysis of Iron, Steel and Alloy: the Neocuproine-chloroform Extraction Photometric Method for the Determination of Copper Content
GB/T 223.23 Iron Steel and Alloy - Determination of Nickel Content - the Dimethylglyoxime Spectrophotometric Method
GB/T 223.26 Iron Steel and Alloy - Determination of Copper Content - the Thiocyanate Spectrophotometric Method
GB/T 223.59 Iron Steel and Alloy - Determination of Phosphorus Content - Bismuth Phosphomolybdate Blue Spectrophotometric Method and Antimony Phosphomolybdate Blue Spectrophotometric Method
GB/T 223.60 Methods for Chemical Analysis of Iron, Steel and Alloy - the Perchloric Acid Dehydration Gravimetric Method for the Determination of Silicon Content
GB/T 223.63 Methods for Chemical Analysis of Iron, Steel and Alloy - the Sodium (Potassium) Periodate Photometric Method for the Determination of Manganese Content
GB/T 223.68 Methods for Chemical Analysis of Iron, Steel and Alloy - the Potassium Iodate Titration Method after Combustion in the Pipe Furnace for the Determination of Sulfur Content
GB/T 223.69 Iron Steel and Alloy - Determination of Carbon Contents - Gas-volumetric Method after Combustion in the Pipe Furnace
GB/T 223.77 Methods for Chemical Analysis of Iron, Steel and Alloy - the Flame Atomic Absorption Spectrometric Method for the Determination of Calcium Content
GB/T 223.82 Steel and iron - Determination of Hydrogen Content - Inert Gas Impulse Fusion Heat Conductivity Method
GB/T 223.84 Steel and Alloy - Determination of Titanium Content - Diantipyrylmethane Spectrophotometric Method
GB/T 224-2008 Determination of Depth of Decarburization of Steel
GB/T 225 Steel - Hardenability Test by End Quenching (Jominy Test)
GB/T 226 Etch Test for Macrostructure and Defect of Steels
GB/T 228.1 Metallic Materials - Tensile Testing - Part 1: Method of Test at Room Temperature
GB/T 229 Metallic Materials - Charpy Pendulum Impact Test Method
GB/T 231.1 Metallic Materials - Brinell Hardness Test - Part 1: Test Method
GB/T 702-2008 Hot-rolled Round and Square Steel Bars - Dimension, Shape, Weight and Tolerance
GB/T 905-1994 Dimension, Shape, Weight and Tolerance for Cold-drawn Round, Square and Hexagonal Steels
GB/T 908-2008 Forged Bars - Dimension, Shape, Weight and Tolerance
GB/T 1979 Standard Diagrams for Macrostructure and Defect of Structural Steels
GB/T 2101 General Requirement of Acceptance, Packaging, Marking and Certification for Section Steel
GB/T 2975 Steel and Steel Products - Location and Preparation of Test Pieces for Mechanical Testing
GB/T 3207-2008 Bright Steel
GB/T 4162 Forged and Rolled Steel Bars - Method for Ultrasonic Examination
GB/T 4336 Standard Test Method for Spark Discharge Atomic Emission Spectrometric Analysis of Carbon and Low-alloy Steel (Routine Method)
GB/T 6394-2002 Metal-methods for estimating the average grain size
GB/T 10561-2005 Steel - Determination of Content of Nonmetallic Inclusions - Micrographic Method Using Standards Diagrams
GB/T 11261 Steel and Iron - Determination of Oxygen Content - the Pulse Heating Inert Gas Fusion - Infrared Absorption Method
GB/T 15711 Steel Products - Method for Etch Test of Tower Sample
GB/T 20066 Steel and Iron - Sampling and Preparation of Samples for the Determination of Chemical Composition
GB/T 20123 Steel and Iron - Determination of Total Carbon and Sulfur Content Infrared Absorption Method after Combustion in an Induction Furnace (Routine Method)
GB/T 20125 Low-alloy Steel - Determination of Multi-Element Contents - Inductively Coupled Plasma Atomic Emission Spectrometric Method
YB/T 4307 Iron Steel and Alloy - Determination of Oxygen, Nitrogen and Hydrogen Contents - Pulse Heating Inert Gas Fusion - Time of Flight Mass Spectrum (Routine Method)
3 Classification and Code
3.1 According to metallurgical quality, steels are classified into:
a) fine steel
b) high-grade fine steel (designation followed by "A");
3.2 According to smelting process, steels are classified into:
a) vacuum-degassed steel;
b) electroslag remelting steel.
3.3 According to processing way, steels are classified into:
a) hot-forged (WHF) steel;
b) hot-rolled (WHR) steel
c) cold drawn (WCD) steel;
d) bright steel;
1) flayed steel (SF)
2) polished steel (SP).
3.4 According to the usage and processing purposes, steels are classified into:
a) steel for pressure work (UP);
b) steel for cut work (UC).
4 Order Contents
Order contract in accordance with this standard shall include the following information at least:
a) standard number;
b) designation;
c) dimension and accuracy;
d) weight and/or quantity;
e) smelting process (see 6.2);
f) delivery state (see 6.3);
g) metallurgical quality (see 6.2, 6.7~6.9);
h) applied processing method (see 6.13);
i) items or indexes that shall be indicated in the contract subjected to the negotiation by the supplier and the demander;
j) other special requirements.
5 Dimension, Shape and Weight
5.1 Dimension
5.1.1 Diameter and tolerance
The diameter and tolerance of steel shall be in accordance with those specified in Table 1.
Table 1 Diameter and Tolerance of Steel
Steel type Nominal diameter, mm, not greater than Tolerance
Hot-rolled round steel 310 Second group in Table 1 of GB/T 702-2008
Hot-forged round steel 400 First group in GB/T 908-2008
Cold-drawn round steel 60 Grade h11 a in GB/T 905-1994
Bright round steel 120 Grade 11(h11) a in Table 4 of GB/T 3207-2008
a Agreed by the supplier and the demander and being indicated in the contract, the steels may also be delivered according to other grades.
5.1.2 Length
5.1.2.1 The delivery length of steel shall meet those specified in Table 2.
Table 2 Length of Steel Dimensions in mm
Steel type Normal length a Whether delivered in short length is allowed
Hot-rolled round steel 3 000~12 000 Not allowed
Hot-forged round steel 2 000~6 000 Not allowed
Cold-drawn round steel 3 000~6 000 Short length steels with length not less than
2 000mm are allowed to be delivered, but the weight shall not exceed 10% total weight of this batch.
Bright round steel 4 000~7 000
a Agreed by the supplier and the demander and being indicated in the contract, steels of other length requirements may also be provided.
5.1.2.2 Steels shall be delivered by uniform length within the specified length range, and the length difference between the longest and shortest steels in each bundle shall not be larger than 1 000mm.
5.1.2.3 Steels may be delivered according to specified length or double length, their length shall be indicated in the contract and the tolerance is +50 0mm.
5.2 Shape
5.2.1 Curvature and ovality
The curvature and ovality of steels shall be in accordance with those specified in Table 3. As agreed by both the supplier and the demander and indicated in the contract, steels of other curvatures and ovalities may also be provided.
Contents of GB/T 3203-2016
Foreword i
1 Scope
2 Normative References
3 Classification and Code
4 Order Contents
5 Dimensions, Shapes and Weights
6 Technical Requirements
7 Test Methods
8 Inspection Rules
9 Packaging, Marking and Quality Certificate
