1. Scope
This standard specifies grade, dimension, shape, weight, allowable deviation, technical requirements, test methods, test rules, packaging, mark and quality certificate.
This standard is applicable to the steel plate, steel strip, section steel and steel bar of the high strength low alloy structural steels which are with general structure or is used for the engineering.
2. Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. For date reference, the subsequent amendments to (excluding amending error in the text) or revisions of, any of these publications do not apply. And parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, its latest edition referred to applies.
GB/T 222 Allowable Deviation of Steel Product Analysis
GB/T 223.5 Iron and steel: reduced silicate spectrophotometric method for the determination of the acid soluble silicon and all silicon content
GB/T 223.9 Steel and alloy: the chrome azurol S spectrophotometric method for the determination of aluminum content;
GB/T 223.12 Chemical analysis method for steel and alloy: the sodium carbonate separation-diphenyl carbazide photometric method for the determination of chromium content
GB/T 223.14 Chemical analysis method for steel and alloy: the N-benzoy-N-phenylhydroxylamine extraction photometric method for the determination of vanadium content
GB/T 223.16 Chemical analysis method for steel and alloy: the chromotropic acid photometric method for the determination of titanium content
GB/T 223.19 Chemical analysis method for steel and alloy: the neocuproine-chloroform extraction photometric method for the determination of copper content
GB/T 223.23 Steel and alloy: the dimethylglyoxime spectrophotometric method for the determination of nickel content
GB/T 223.26 Steel and alloy: the thiocyanate spectrophotometric method for the determination of molybdenum content
GB/T 223. 37 Chemical analysis method for steel and alloy: the indophenol blue photometric method for the determination of nitrogen content after distillation separation;
GB/T 223. 40 Steel and alloy: the chlorsulphophenol S spectrophotometric method for the determination of niobium content;
GB/T 223. 62 GB/T 223.62 Chemical analysis method for steel and alloy: phosphorus quantity measured according to butyl acetate extraction-photometric method;
GB/T 223. 63 Chemical analysis method for steel and alloy: the sodium (potassium) periodate photometric method for the determination of manganese content
GB/T 223. 67 Iron and steel and alloy: the methylene blue spectrophotometric method for the determination of sulfur content
GB/T 223. 69 Iron and steel and alloy: the gas-volumetric method after combustion in the pipe furnace for the determination of carbon content
GB/T 223. 78 Chemical analysis method for steel and alloy: curcumin direct photometric method for the determination of boron content
GB/T 228 Metallic Materials-Tensile Testing at Ambient Temperature (GB/T 228-2002, eqv ISO 6892:1998)
GB/T 229 Metal material- Charpy pendulum impact test (GB/T 229-2007, ISO 148-1: 2006, MOD)
GB/T 232 Metal materials: bending test method (GB/T 232-1999, eqv ISO 7438:1985)
GB/T 247 General rule of acceptance, package, mark and certification for steel plates (sheets) and steel strips
GB/T 2101 General Rule of Acceptance, Package, Mark and Certification for Section Steel
GB/T 2975 Steel and Steel Products-Mechanical Testing for Sampling Location and Specimen Preparation (GB/T 2975-1998, eqv ISO 377: 1997)
GB/T 4336 Method for Photoelectric Emission Spectroscopic Analysis of Carbon Steel and Medium and Low Alloy Steel (conventional)
GB/T 5313 Through-thickness property steel plate (GB/T 5313-1985, eqv ISO 7778:1983)
GB/T 17505 Steel and steel products: general technical delivery requirements (GB/T 17505-1998, eqv ISO 404: 1992)
GB/T 20066 Steel and iron-sampling and preparation of samples for the determination of chemical composition (GB/T 20066-2006, 150 14284:1996, IDT)
GB/T 20125 Low alloy steel-inductively coupled plasma emission spectrometer for the determination of multielement content
YB/T 081 Rule for rounding off of numberical values and judgment of testing values for technical standards of metallurgy
3. Terms and Definitions
3.1 Thermomechanical rolling
The ultimate deformation is a rolling procedure, which is carried out within a certain temperature range. This procedure makes the material obtain the special performance which is not obtained only through heat treatment.
Note 1: If the temperature is increased to 580℃ after the rolling, the material strength value may be reduced. If it is necessary to increase the temperature to 580℃, it shall be supplied by the seller.
Note 2: Thermomechanical rolling delivery state may contain accelerated cooling or accelerated cooling plus tempering (contain self tempering), but excludes direct quenching or quenching plus tempering.
3.2 Normalizing rolling
The ultimate formation is a rolling procedure, which is carried out within a certain temperature range. This procedure makes the material obtain the performance which is equivalent to that after the normalizing.
