Q235 What are the differences in mechanical properties between hot-rolled and cold-rolled coils?
A: Due to cold rolling and annealing, cold-rolled coils have slightly lower yield strength (200-235 MPa), similar tensile strength, higher elongation (≥30%), and slightly higher surface hardness than hot-rolled coils.
Q235 steel coils have excellent cold working properties.
A: They have excellent cold bending, cold stamping, and cold shearing properties, and can be directly bent, rolled, and stamped without preheating, making them a preferred choice for general cold working steels.
Q235 steel coils can be strengthened by heat treatment.
A: No, as a low-carbon steel, heat treatment (such as quenching and tempering) has no significant effect on strength improvement. Surface hardness can only be improved through cold working (such as cold rolling and cold drawing).
Q235 steel coils have impact toughness suitable for low-temperature environments.
A: Q235B is only suitable for environments ≥0℃. For low-temperature environments ≤0℃, Q235C (0℃ impact)/Q235D (-20℃ impact) should be selected, but these types of steel coils are rarely produced. In low-temperature scenarios, Q355 series is generally used as a substitute.
What are the weldability properties of Q235 steel coils?
A: Excellent weldability. It has low carbon content and no alloying elements, and can be welded using all conventional welding methods such as manual arc welding, CO2 gas shielded welding, and submerged arc welding. No preheating or post-weld heat treatment is required, and the weld joint strength is consistent with the base metal.