GB/T 20564.6-2022 English PDF (GBT20564.6-2022)

This document specifies the classification and designation expression method, order contents, dimensions, shapes, weights, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of continuously cold rolled transformation induced plasticity high strength steel sheet and strip for automobile. This document is applicable to continuously cold rolled transformation induced plasticity high strength steel sheet and strip (with a thickness of 0.50 mm ~ 2.5 mm) mainly used to fabricate structural parts and reinforcements of automobile.

GB/T 20564.6-2022
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.50
CCS H 46
Replacing GB/T 20564.6-2010
Continuously Cold Rolled High Strength Steel Sheet and
Strip for Automobile - Part 6.Transformation Induced
Plasticity Steel
ISSUED ON. JULY 11, 2022
IMPLEMENTED ON. FEBRUARY 1, 2023
Issued by. State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword... 3
Introduction... 5
1 Scope... 7
2 Normative References... 7
3 Terms and Definitions... 9
4 Classification and Designation Expression Method... 9
5 Order Content... 10
6 Dimensions, Shapes and Weights... 11
7 Technical Requirements... 11
8 Test Methods... 14
9 Inspection Rules... 15
10 Packaging, Marking and Quality Certificate... 15
11 Comparison of Similar Designations in China and Foreign Countries... 15 Appendix A (informative) Reference Values of Chemical Composition (melting analysis) of Steel Sheet and Strip... 16
Appendix B (informative) Comparison of Similar Designations in China and Foreign Countries... 17
Bibliography... 18
Continuously Cold Rolled High Strength Steel Sheet and
Strip for Automobile - Part 6.Transformation Induced
Plasticity Steel
1 Scope
This document specifies the classification and designation expression method, order contents, dimensions, shapes, weights, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of continuously cold rolled transformation induced plasticity high strength steel sheet and strip for automobile.
This document is applicable to continuously cold rolled transformation induced plasticity high strength steel sheet and strip (with a thickness of 0.50 mm ~ 2.5 mm) mainly used to fabricate structural parts and reinforcements of automobile (hereinafter referred to as “the steel sheet and strip”).
2 Normative References
The contents of the following documents constitute indispensable clauses of this document through the normative references in this text. In terms of references with a specified date, only versions with a specified date are applicable to this document. In terms of references without a specified date, the latest version (including all the modifications) is applicable to this document. GB/T 223.9 Iron, Steel and Alloy - Determination of Aluminum Content - Chrome Azurol S Photometric Method
GB/T 223.12 Methods for Chemical Analysis of Iron, Steel and Alloy - The Sodium Carbonate Separation-diphenyl Carbazide Photometric Method for the Determination of Chromium 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 223.53 Methods for Chemical Analysis of Iron, Steel and Alloy - The Flame Atomic Absorption Spectrophotometric Method for the Determination of Copper Content GB/T 223.54 Methods for Chemical Analysis of Iron, Steel and Alloy - The Flame Atomic Absorption Spectrophotometric Method for the Determination of Nickel Content 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 Iron, Steel and Alloy - Determination of Manganese Content - Sodium (potassium) Periodate Spectrophotometric Method
GB/T 223.64 Iron, Steel and Alloy - Determination of Manganese Content - Flame Atomic Absorption Spectrometric Method
GB/T 223.85 Steel and Iron - Determination of Sulfur Content - Infrared Absorption Method after Combustion in an Induction Furnace
GB/T 223.86 Steel and Iron - Determination of Total Carbon Content - Infrared Absorption Method after Combustion in an Induction Furnace
GB/T 228.1-2021 Metallic Materials - Tensile Testing - Part 1.Method of Test at Room Temperature
GB/T 247 General Rule of Acceptance, Package, Mark and Certification for Steel Plates (sheets) and Strips
GB/T 708 Dimension, Shape, Weight and Tolerance for Cold-rolled Steel Strip and Sheet GB/T 2523 Measuring Method of Surface Roughness, Peak Count and Waviness for Cold- rolled Metal Sheet and Strip
GB/T 2975 Steel and Steel Products - Location and Preparation of Samples and Test Pieces for Mechanical Testing
GB/T 4336 Carbon and Low-alloy Steel - Determination of Multi-element Contents - Spark Discharge Atomic Emission Spectrometric Method (routine method)
GB/T 5028 Metallic Materials - Sheet and Strip - Determination of Tensile Strain Hardening Exponent
GB/T 8170 Rules of Rounding off for Numerical Values and Expression and Judgement of Limiting Values
GB/T 17505 Steel and Steel Products - General Technical Delivery Requirements GB/T 18253-2018 Steel and Steel Products - Types of Inspection Documents 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
3 Terms and Definitions
The following terms and definitions are applicable to this document.
3.1 Transformation Induced Plasticity Steel; TR
Transformation induced plasticity steel refers to a type of steel whose microstructure is mainly ferrite, bainite and retained austenite, and during the forming process, the retained austenite may be transformed into a martensitic structure.
NOTE. transformation induced plasticity steel has a relatively high work hardening rate, uniform elongation and tensile strength. In comparison with dual phase steel with equivalent tensile strength, transformation induced plasticity steel has a higher elongation. 4 Classification and Designation Expression Method
4.1 Designation Expression Method
The designation of the steel sheet and strip is composed of three parts. the initials “CR” of the English “Cold Rolled”, the specified minimum yield strength value / specified minimum tensile strength value, and the first two letters “TR” of the English “Transformation Induced Plasticity”. Example. CR380/590TR, in which.
CR---the initials of the English “Cold Rolled”;
380/590---380.the specified minimum yield strength value, 590.the specified minimum tensile strength value, expressed in (MPa);
TR---the first two letters of the English “Transformation Induced Plasticity”. 4.2 Classification
4.2.1 The designations and recommended purposes of the steel sheet and strip are shown in Table 1.
d) Specifications, dimensions and unevenness accuracy;
e) Surface quality level;
f) Surface structure;
g) Edge state;
h) Packaging mode;
i) Weight;
j) Purposes;
k) Other special requirements.
5.2 If the dimensions, unevenness accuracy, surface quality level, surface structure type, edge state and packaging are not specified in the order contract, then, the products in this document shall be delivered with ordinary dimensions and unevenness accuracy, and a relatively advanced surface as trimmed steel sheet or strip with a pitted surface structure, and be packed in accordance with the packaging mode provided by the supply-side.
6 Dimensions, Shapes and Weights
The dimensions, shapes, weights and allowable deviations of the steel sheet and strip shall comply with the stipulations of GB/T 708.
7 Technical Requirements
7.1 Chemical Composition
The reference values of the chemical composition (melting analysis) of steel are shown in Appendix A. If the demand-side has requirements for the chemical composition, they shall be negotiated during ordering.
7.2 Smelting Method
The steel used for the steel sheet and strip shall be smelted by oxygen converter or electric furnace. Unless it is otherwise specified, the smelting method shall be selected by the supply- side.
7.3 Delivery State
7.3.1 The steel sheet and strip shall be delivered in a flat state after annealing. 7.3.2 Usually, the steel sheet and strip are delivered with oil. The applied oil film shall be able to be removed through an alkaline aqueous solution or a common solvent. Under the usual 9 Inspection Rules
9.1 The inspection and acceptance inspection of the steel sheet and strip shall be carried out by the inspection department of the supply-side.
9.2 The steel sheet and strip shall receive the acceptance inspection in batches. Each inspection batch shall be composed of steel sheet or strip of the same designation, specification and processing state. The weight of each batch shall be not greater than 30 t. For steel strip with a coil weight greater than 30 t, each coil shall be regarded as an inspection batch. 9.3 The sampling size and sampling method of the steel sheet and strip shall comply with the stipulations of Table 8.
9.4 The re-inspection and determination rules of the steel sheet and strip shall comply with the stipulations of GB/T 17505.
9.5 The inspection results of chemical composition and mechanical properties shall be rounded off in accordance with the rounding-off value comparison method; the rounding-off rules shall comply with the stipulations of GB/T 8170.
10 Packaging, Marking and Quality Certificate
The packaging, marking and quality certificate of the steel sheet and strip shall comply with the stipulations of GB/T 247.The type of the quality certificate (inspection document) shall comply with the stipulations of GB/T 18253-2018.When the type of inspection document is not specified, comply with Type 3.1 in GB/T 18253-2018.If the demand-side has special demands for the packaging, they may be negotiated during ordering.
11 Comparison of Similar Designations in China and Foreign
Countries
The comparison of similar designations of this document and international standards is shown in Appendix B.