What tonnage equipment is needed for stamping SPCD rolls?
A: It depends on the size and deformation of the stamped part. For small, conventional stamped parts, a 50-100 ton machine is sufficient. For large, complex stamped parts such as automotive chassis, a 200-500 ton large stamping machine is required to ensure forming quality.
What changes occur in the properties of SPCD rolls after annealing?
A: Annealing completely eliminates internal stress, reduces hardness and yield strength, and significantly improves plasticity and toughness. It enhances the deformation capacity during stamping, effectively reducing processing problems such as cracking and springback.
What indicators should be focused on during SPCD roll inspection?
A: The key indicators to inspect are chemical composition, surface quality (no scratches, pitting, or other defects), thickness tolerance, mechanical properties (yield strength, tensile strength), and bending performance. These indicators directly affect processing feasibility and finished product quality.
What causes locally high hardness in SPCD rolls?
A: This is mostly due to substandard annealing processes, such as insufficient annealing temperature or holding time, resulting in incomplete elimination of work hardening in certain areas. It could also be caused by uneven rolling pressure during cold rolling, leading to uneven hardness distribution.
What methods besides galvanizing can improve the corrosion resistance of SPCD coils?
A: Electroplating with nickel, spraying with anti-corrosion coatings, etc., can be used. Passivation treatment can also be performed to form a dense oxide film on the surface. For short-term use, basic corrosion protection can be achieved by applying rust-preventive paint.