What are the core standards for SPCC cold-rolled coils?
A: The core standard is Japanese Industrial Standard JIS G 3141-2011 "Cold-rolled Carbon Steel Sheets and Strips". Some domestic manufacturers may refer to the national standard GB/T 11253-2007 "Cold-rolled Carbon Structural Steel Sheets and Strips".
What are the inspection items for SPCC cold-rolled coils?
A: Routine inspection items include: chemical composition analysis (C, Mn, S, P, etc.), mechanical property testing (tensile strength, yield strength, elongation), dimensional tolerance inspection (thickness, width, length), surface quality inspection, and sheet shape inspection.
What is the hardness range of SPCC cold-rolled coils? What are the commonly used testing methods?
A: Annealed SPCC has a Brinell hardness (HB) ≤130 and a Vickers hardness (HV) ≤150. Common testing methods include Brinell hardness testers or Vickers hardness testers. Rockwell hardness testers (HRB) can also be used, with a hardness value ≤70 HRB.
How to distinguish between the annealed and hardened states of SPCC cold-rolled coils? A: Annealed state: Good plasticity, easy to bend, smooth surface, elongation ≥28%; Hardened state: High strength, poor plasticity, prone to cracking when bent, elongation typically ≤10%, surface may have slight rolling marks.
What information is included in the quality certificate of SPCC cold-rolled coils? A: It includes the grade, standard number, specifications (thickness × width × length), production batch number, chemical composition, mechanical properties, dimensional tolerances, surface quality grade, inspection conclusion, production date, and manufacturer's name.