1. The main working parts of the mold material problems, improper selection. Poor material performance, not wear-resistant, die steel is not refined, with a large number of smelting defects, concave and convex die, forging billet modified forging art is imperfect, the remains of heat treatment hidden trouble.
2. Die structure design problem, the die structure is unreasonable. Slender convex die without the design of reinforcement device, out of the material opening up the heap, unloading force over the ambassador convex die under alternating load and so on.
3. The molding process is not perfect, mainly in the convex, concave die forging billet internal quality is poor, heat treatment technology and process problems, resulting in convex, concave die quenching, soft spots and uneven hardness. Sometimes micro-cracks, even cracks, grinding polishing is not in place, the surface roughness value is too large.
4. No lubrication or lubrication but ineffective.