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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 1222-2007 Spring Steels. This standard technically differs from GB/T 1222-2007 mainly in:
——The diameter of round spring steel, as well as the side length of square spring steel, is extended to 120 mm, the thickness of flat spring steel to 60 mm, and the reeled rod diameter of spring steel to 40 mm (see Clause 1);
——Terms and definitions are added (see Clause 3);
——Designations, i.e. 80, 70Mn, 38Si2, 40SiMnVBE (patent designation), 55SiCrV, 56Si2MnCr, 60CrMnMo, 51CrMnV, 52CrMnMoV, 60Si2MnCrV, 52Si2CrMnNi, and the relevant technical requirements are added (see 6.1.1, 6.4 and Annexes B and C);
——The composition ranges of some designations are modified and the requirements of phosphorus and sulfur contents are tightened (see Table 1);
——The requirements for oxygen content are added to alloy spring steel (see 6.1.2);
——The acceptable level of macroscopic defect is tightened (see 6.6.2; 5.6.2 of Edition 2007);
——The acceptable level of nonmetallic inclusion is classified and the requirements for DS type inclusions are added (see 6.7; 5.7 of Edition 2007);
——the requirement for the decarburized depth of hot rolled materials is tightened and classification is specified (see 6.8.1; 5.8.1 of Edition 2007);
——Section profile and dimensional requirements are added to planar large-arc flat spring steels and planar rectangular flat spring steels, and the section profile of single-side double-slot flat spring steel and corresponding requirements are cancelled (see Annex A);
——The main applications of designation and cross-reference between domestic and foreign designations are added (see Annexes B and C).
This standard was proposed by the China Iron and Steel Association.
This part is under the jurisdiction of the National Technical Committee on Steel and Iron of Standardization Administration of China (SAC/TC 183).
The previous editions of the standard superseded by this standard are as follows:
——GB/T 1222-1975, GB/T 1222-1984, GB/T 1222-2007.
Introduction
For those declaring conformity with this document, please note that the contents in Table 1, 6.1.2, Table 3, Table 4, D.2 and E.2 involve use of the patented steel 40SiMnVBE.
The issuing body of this document takes no position over the authenticity, validity and scope of the patent.
The patent holder has already expressed to the issuing body of this document that he would like to negotiate with any applicant about the patent authorization license under reasonable and nondiscriminatory terms and conditions. The patent holder's statement has documented with the issuing body of this document. For relevant information, please refer to:
Patent holder: Han Jianzhong
Address: No. 24, Building 11, Courtyard 15, Jingwu Road, Jinshui District, Zhengzhou, Henan
Post code: 450000
Attention is drawn to the possibility that some contents, other than the above-mentioned patent, of this document may also be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
Spring Steels
1 Scope
This standard specifies the terms and definitions, ordering information, size, profile and weight, technical requirements, test methods, inspection rules, packaging, marking and quality certification for hot-rolled, forged and cold drawn spring steels.
This standard is applicable to round spring steels and square steels (hereinafter referred to as "bars") not greater than 120 mm in nominal diameter or side length, flat spring steels not greater than 160 mm in nominal width or 60 mm in nominal thickness, and spring steel reeled rods not greater than 40 mm in nominal diameter.
The designation and chemical composition specified in this standard are also applicable to ingot steel, steel billet and their products.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 222 Permissible Tolerances for Chemical Composition of Steel Products
GB/T 223.5 Steel and Iron—Determination of Acid-soluble Silicon and Total Silicon Content—Reduced Molybdo-silicate Spectrophotometric Method
GB/T 223.11 Iron, Steel and Alloy—Determination of Chromium Content—Visual Titration or Potentiometric Titration Method
GB/T 223.13 Methods for Chemical Analysis of Iron, Steel and Alloy—The Ammonium Ferrous Sulfate Titration Method for the Determination of Vanadium Content
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 Molybdenum Content—The Thiocyanate Spectrophotometric Method
GB/T 223.43 Iron, Steel and Alloy—Determination of Tungsten Content—Gravimetric Method and 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 223.64 Iron, Steel and Alloy—Determination of Manganese Content—Flame Atomic Absorption Spectrometric Method
GB/T 223.72 Iron Steel and Alloy—Determination of Sulfur Content—Gravimetric Method
GB/T 223.75 Iron, Steel and Alloy—Determination of Boron Content—Methanol Distillation-Curcumin Photometric Method
GB/T 223.76 Methods for Chemical Analysis of Iron, Steel and Alloy—The Flame Atomic Absorption Spectrometric Method for the Determination of Vanadium Content
GB/T 223.86 Iron, Steel and Alloy—Determination of Total Carbon Content—Infrared Absorption Method after Combustion in an Induction Furnace
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 Material—Tensile Test—Part 1: Method of Test at Room Temperature
GB/T 231.1 Metallic Materials—Brinell Hardness Test—Part 1: Test Method
GB/T 702 Hot-rolled Steel Bars—Dimensions, Shape, Weight and Tolerances
GB/T 905 Dimension, Shape, Weight and Tolerance for Cold-drawn Round, Square and Hexagonal Steels
GB/T 908 Forged Bars—Dimensions, Shape, Weight and Tolerances
GB/T 1814 Inspection Method for Steel Work Fractures
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 3078 Quality Structural Steel Cold Drawn Bars
GB/T 3207 Bright Steel
GB/T 4162 Forged and Rolled Steel Bars—Method for Ultrasonic Testing
GB/T 4336 Standard Test Method for Spark Discharge Atomic Emission Spectrometric Analysis of Carbon and Low-alloy Steel (Routine Method)
GB/T 5216-2014 Structural Steels Subject to End-quench Hardenability Requirements
GB/T 6394 Metal—Methods for Estimating the Average Grain Size
GB/T 7736 Ultrasonic Inspecting Method for Macro-Structure and Imperfection of Steel
GB/T 8170-2008 Rules of Rounding Off for Numerical Values & Expression and Judgment of Limiting Values
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 13298 Inspection Methods of Microstructure for Metals
GB/T 13299 Steel—Determination of Microstructure
GB/T 13302 Steel—Determination of Area Content of Graphite-Micrographic Method Using Diagrams
GB/T 14981 Dimensions, Shape, Mass and Tolerances for Hot-rolled Wire Rods
GB/T 17505 Steel and Steel Products—General Technical Delivery Requirements
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 4413 Metallographic Method for Assessment of Center Segregation for High-Carbon-Steel Reeled Rods
3 Terms and Definitions
For the purpose of this standard, the terms and definitions given in GB/T 3207 and the following apply.
3.1
spring steels
steel of elastic property used for manufacturing spring or elastic element
Note: The elasticity of steel depends on the capacity for elastic deformation, i.e. to the specified extent, the capacity of elastic deformation enables withstanding a certain load and no permanent deformation occurs after the load is removed.
4 Ordering Information
The order contract or order according to this standard shall include the following information:
a) Standard reference;
b) Product name;
c) Designation or unified numerical code;
d) Delivery weight (or quantity);
e) Dimensions and accuracies (see Clause 5);
f) Delivery condition or code (see 6.3);
g) Hardenability requirement, if any (see 6.5);
h) Nonmetallic inclusion group (see 6.7);
i) Decarburized layer group (see 6.8);
j) Special requirement, if any (see 6.10).
5 Size, Profile and Weight
5.1 The size, profile and tolerances of hot rolled bar shall meet the relevant requirements of GB/T 702 and shall be specifically indicated in the contract.
5.2 The size, profile and tolerances of forged bar shall meet the relevant requirements of GB/T 908 and shall be specifically indicated in the contract.
5.3 The size and its tolerance of hot rolled reeled rod shall meet the relevant requirements of GB/T 14981 and shall be specifically indicated in the contract.
5.4 The size, profile and their tolerances of hot-rolled flat steel shall meet the relevant requirements of Annex A and shall be specifically indicated in the contract.
5.5 The size, profile and tolerances of cold-drawn bar shall meet the relevant requirements of GB/T 905 and shall be specifically indicated in the contract.
5.6 The size, profile and their tolerances of silver steel shall meet the relevant requirements of GB/T 3207 and shall be specifically indicated in the contract.
5.7 Steels are delivered by actual weight.
6 Technical Requirements
6.1 Designation and chemical composition
6.1.1 The designation, unified numerical code and chemical composition (heat analysis) of steel shall be in accordance with those specified in Table 1. As agreed by the supplier and the purchaser and noted in the contract, other designation of spring steel may also be supplied.
Foreword i
Introduction iii
1 Scope
2 Normative References
3 Terms and Definitions
4 Ordering Information
5 Size, Profile and Weight
6 Technical Requirements
7 Test Methods
8 Inspection Rules
9 Packaging, Marking and Quality Certificate
Annex A (Normative) Section Profile & Nominal Size and Shape of Hot-rolled Flat Steel
Annex B (Informative) Main Characteristics and Application of Designations
Annex C (Informative) Cross Reference of Designations between This Standard and Domestic & Foreign Standards
Annex D (Informative) Main Technical Parameters of 28SiMnB and 40SiMnVBE Steels
Annex E (Informative) End Hardenability Band of Some Designations
Bibliography