Q: What are the cold bending performance standards for Q235 coils?
A: According to GB/T 232, no cracks should appear after a 180° cold bending test; the mandrel diameter d=1.5a (a is the sample thickness), adjusted according to product standards.
Q: What is the hardness range of Q235 coils?
A: Hot-rolled HB 100–140, no mandatory standard, for reference only, not for acceptance.
Q: What is the production process for Q235 hot-rolled coils?
A: Blast furnace ironmaking → converter steelmaking → LF/VD refining → continuous casting billet → heating furnace → rough rolling → finish rolling → laminar flow cooling → coiling → inspection → warehousing.
Q: What is the effect of coiling temperature on the properties of Q235 coils?
A: Coiling temperature 550–650℃; too low a temperature can lead to higher strength and lower plasticity; too high a temperature can cause banded structures, affecting cold working and welding.
Q: What are the main application areas of Q235 coils? A: Buildings (steel structures, color steel tile base plates), machinery (supports, boxes), vehicles (carriage panels), home appliances (shells, bases), pipes (welded pipe base materials), agricultural machinery and general components.