Adopt qualified 316 stainless steel hot rolled wire rod as raw material. Conduct strict incoming inspection including chemical composition analysis, mechanical property test, surface defect check and dimension measurement to verify compliance with ASTM standards. Remove surface scale, cracks and inclusion defects. Sort wire rods according to target wire diameter to prepare for drawing operation.
2.Surface Pickling & Lubrication Treatment:
Carry out pickling process to eliminate oxide scale formed during hot rolling. Clean and neutralize the rod surface thoroughly to avoid residual acid corrosion. Apply professional drawing lubricant evenly on the rod surface, forming a stable lubrication film. This reduces friction between die and workpiece during cold drawing, prevents surface scratches and improves wire surface quality.
3.Multi-pass Cold Drawing:
Perform multi-stage cold drawing through series of drawing dies with gradually reduced aperture. Control drawing speed and reduction rate of each pass reasonably to avoid over-stress and wire breakage. Cold drawing improves tensile strength and dimensional accuracy of the wire, precisely shaping the wire to the required intermediate diameter. Clean the wire surface after each drawing pass to remove residual lubricant.
4.Intermediate Annealing:
After certain drawing passes, implement solution annealing treatment under controlled inert atmosphere. Heat the wire to specified temperature and hold for proper time, then cool slowly. The annealing process relieves work hardening and internal stress generated by cold deformation, restores ductility of 316 stainless steel, so that the wire can continue subsequent drawing without cracking.
5.Finishing Drawing & Surface Finishing:
Conduct final precision drawing to achieve the exact finished wire diameter and tolerance requirement. Options of surface finishing include bright annealing, pickling or matte treatment according to customer demands. Straighten the wire to eliminate bending and twisting, then trim both ends. Check surface condition to ensure no pits, scratches or burrs on finished wire surface.
6.Final Inspection & Packing:
Carry out full inspection on finished wire, including diameter tolerance, tensile strength, elongation, surface quality and corrosion resistance sampling test. Qualified products are wound into coils with specified weight. Wrap coils with anti-moisture protective paper and plastic film, then fix and mark with product grade, diameter, batch number and specification. Store in dry warehouse before shipment.