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Carbon structural steel and low alloy structural steel hot rolled and cold rolled thin steel plate and steel strip are all important material for manufacturing autos and other products. The general production requirements for both are the same, which should have higher strength limit and better plasticity, mechanical property and welding performance. This article discusses the production requirements, physical and chemical requirements, defects and other aspects of carbon structural steel and low-alloy structural steel hot rolling and cold rolling thin steel plate and steel belt (GB / T912-1989, GB / T11253-1989).
Carbon Structural Steel and Low Alloy Structural Steel Hot Rolling and Cold Rolling Thin Steel Plate and Steel Belt (1) General Technical Requirements
(1) Chemical Composition Requirements
Carbon structural steels and low alloy structural steels should meet the chemical composition requirements specified in GB/T912 and GB/T11253-1989. When the yield strength of the steel is not greater than 275MPa, the carbon tensile strength is not more than 510MPa, and the number of steel grades is not specified, the carbon equivalent value Ceq should also meet the requirements specified in GB/T912-1989 and GB/T11253-1989.
(2) Mechanical Properties
Carbon structural steels and low alloy structural steels should meet the requirements of GB/T912-1989 and GB/T11941 when the yield strength of the steel is not greater than 275MPa and the tensile strength is not more than 510MPa. The number of steel grades specified should meet the requirements of GB/T912-1989 and GB/T11941 when the yield strength of steel is greater than 275MPa and the tensile strength is greater than 510MPa.
(3) Heat treatment
For carbon structural steel and low alloy structural steel plates and steel belts, heat treatment should meet the requirements of GB/T912-1989 and GB/T11253-1989.
(4) Quality Requirements
Carbon structural steel and low alloy structural steel plates and steel belts should meet the quality requirements of GB/T912-1989 and GB/T11253-1989.
(2) Physical and Chemical Requirements
(1) Surface Quality
The surface quality requirements for carbon structural steel and low alloy structural steel hot rolling and cold rolling thin steel plate and steel belt should meet the requirements of 9G/T2205-1989 and GB/T2103-1989.
(2) Testing Items
Carbon structural steel and low alloy structural steels should inspect the contents of chemical elements, carbon equivalent values, mechanical properties and other items in accordance with GB/T912-1989 and GB/T11253-1989.
(3) Defects
Carbon structural steel and low alloy structural steels should meet the requirements of GB/T912-1989 and GB/T11253-1989 in terms of weld seam defects, cracks, blistering, rolling surface defects, slag inclusions and other defects.
(3) Other Requirements
When carbon structural steel and low alloy structural steels are hot rolled and cold rolled thin plates and steel belts, other requirements such as thickness deviation, width deviation, flatness, edge trimming and pits should meet the requirements specified in GB/T711-1989 and GB/T710-1988.
In conclusion, carbon structural steel and low alloy structural steel hot rolling and cold rolling thin steel plates and steel belts should meet the general technical requirements, physical and chemical requirements and other requirements specified in GB/T912-1989, GB/T11253-1989, GB/T711-1989 and GB/T710-1988. The production must also meet the requirements of the product quality inspection system for hot rolling and cold rolling thin steel plates and steel belts. Only by meeting the requirements of these standards, the product quality is guaranteed.
