Continuously cold rolled high strength steel sheet and strip for automobile — Part 8: Complex phase steel
1 Scope
This part of GB/T 20564 specifies the term and definition, classification and code, dimension, shape, weight, technical requirements, inspections and tests, packaging, marking and quality certificates for cold rolled complex phase high strength steel sheets and strips (hereinafter referred to as "steel sheets and strips").
The steel sheets and strips specified in this part are mainly used for manufacturing automobile structural members, reinforcing members and some inner and outer panels, and the thickness of the steel sheets and strips is 0.60mm~2.50mm.
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 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 aluminum content — Chrome azurol S photometric method
GB/T 223.11 Iron steel and alloy — Determination of chromium content — Visual titration or potentiometric titration method
GB/T 223.23 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 spectrometric method for the determination of copper 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 Methods for chemical analysis of iron, steel and alloy — The sodium (potassium) periodate photometric method for the determination of manganese content
GB/T 223.64 Methods for chemical analysis of iron, steel and alloy — Flame atomic absorption spectrometric method for the determination of manganese content
GB/T 223.67 Iron steel and alloy — Determination of sulfur content — Methylene blue spectrophotometric method
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 223.71 Methods for chemical analysis of iron, steel and alloy — The gravimetric method after combustion in the pipe furnace for the determination of carbon content
GB/T 223.72 Iron, steel and alloy — Determination of sulfur content — Gravimetric method
GB/T 228.1-2010 Metallic materials — Tensile testing — Part 1: Method of test at room temperature
GB/T 247 General rule of package, mark and certification for steel 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 and peak count for cold-rolled metal sheet (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 — Spark discharge atomic emission spectrometric method (routine method)
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
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)
GB/T 20125 Low-alloy steel — Determination of multi-element contents — Inductively coupled plasma atomic emission spectrometric method
GB/T 20126 Unalloyed steel — Determination of low carbon content — Part 2: Infrared absorption method after combustion in an induction furnace (with preheating)
GB/T 24174 Iron — Determination method for the bake hardening value (BH2)
3 Term and definition
For the purposes of this standard, the following term and definition apply.
3.1
complex phase steel; CP
steel whose microstructure is a small amount of martensite, residual austenite or pearlite distributed on the ferrite or bainite substrate, which is strengthened by fine grain or precipitation of micro-alloying elements and has higher yield strength and better bending properties compared with dual phase steel with the same tensile strength
4 Classification and code
4.1 Designation representation method
The designation of steel sheet and steel strip is composed of the initials "CR" of "Cold Rolled", the specified minimum yield strength value/specified minimum tensile strength value, and the initials "CP" of “Complex Phase”, e.g., CR500/780CP.
Foreword i
1 Scope
2 Normative references
3 Term and definition
4 Classification and code
5 Ordering Information
6 Dimension, shape, weight and tolerance
7 Technical requirements
8 Inspections and tests
9 Packaging, marking and quality certificate
10 Rounding off for numerical values
11 Comparison of similar designations between domestic and foreign standards
Annex A (Informative) Chemical composition of steel
Annex B (Informative) Comparison of similar designations between domestic and foreign standards
