Cold Rolled Quality Structural Steel (GB 3078-82)
Cold rolled quality structural steel is a commonly used steel product in the modern construction industry. It is produced by hot rolling and then cold finishing, which results in a superior quality material that is then further treated to meet specific requirements. GB 3078-82 is a Chinese standard developed for cold rolled quality structural steel.
GB 3078-82 applies to carbon steel and low alloy steel products that are cold rolled for use in applications such as pressure vessels, boilers, bridges, ships, and other general engineering purposes. GB 3078-82 stipulates the chemical composition requirements, physical properties and mechanical properties for cold rolled quality structural steel.
GB 3078-82 defines the chemical composition requirements for three different grades of cold rolled quality structural steel. Grade A steel has the lowest carbon content, with maximum values ranging from 0.12 to 0.20%. Grade B steel has a higher carbon content, with maximum values ranging from 0.20 to 0.35%. Grade C steel has the highest carbon content of all three grades, with maximum values ranging from 0.35 to 0.45%.
GB 3078-82 also addresses the physical properties of cold rolled quality structural steel, enabling traditional performance requirements to be met. For Grade A, Grade B, and Grade C the specified minimum yield strength is ≥ 225MPa, 260MPa, and 290MPa respectively. The elongation at break of Grade A, Grade B, and Grade C steel must be ≥ 18%, 17%, and 16% respectively.
The mechanical properties of cold rolled quality structural steel are also addressed by GB 3078-82. Grade A, Grade B, and Grade C steel must have tensile strengths of ≥ 330MPa, 360MPa, and 400MPa respectively. The minimum bending radius for all grade types of this steel product is 6 times the thickness of the steel.
When purchasing cold rolled quality structural steel, GB 3078-82 should be adhered to. The material purchased should always meet all of the requirements outlined in the standard. Furthermore, buyers should always take measures to ensure that the steel is purchased from a reputable supplier who has a track record of producing material that consistently meets GB 3078-82. Only by doing this can the end user have the confidence that the material has the necessary properties to guarantee satisfactory results in the application.
