The basic types of die failure
Compared with ordinary blanking die, precision die of working condition is bad, the main failure form is: mold edge wear (including of abrasive wear and adhesive wear), the main in the blade profile, mold edge collapse blade, die or intensive burst, fracture and plastic deformation of punch.
Factors affecting the
The main factors affecting the service life of precision punching die are: China international mould net
(1) the structure of fine blanking parts manufacturability (horns, thin walled, cliffs, dimensional tolerance, etc.).
(2) the fine blanking parts material (material, thickness, hardness, plasticity, the surface quality).
(3) the structure of the fine blanking die (strength, stiffness, mold, small punch guidance, exhaust and lubrication).
(mould material (material, size and uniformity of carbide, toughness and hardness).
(mould manufacturing (die forging, machining process, heat treatment, cutting, grinding, assembly).
(6) the operation (the variable height, pressure, speed, precision, cleaning, lubricating workpieces feed).
(7) mold repair (reasonable storage, reasonable stress tempering, grinding, cleaning, rust).
The main ways to improve the fine blanking die life
(1) review the technology of fine blanking parts. Technology of fine blanking parts (especially the radius) has certain influence to the life of fine die, technology for the poor (especially sharp corners), should provide improvement Suggestions to the design department. As part of the relationship between the radius and the die life, general r/t 0.8 or higher is better, such as less than 0.25 leads to low die life.
(2) the fine blanking auto mould material selection and heat treatment. Fine blanking die materials of the main parts, generally choose cr12mov, when the thickness of the parts is greater than 4 mm, convex and concave die can be used w6mo5cr4v2 HSS. For working intensity big, force strict convex die and concave die, then using powder metallurgy steel (v4, asp23, asp30) or cemented carbide gt30. Heat treatment the hardness of convex and concave die generally from 58 to 62 HRC, to wear as the main failure form, shape, simple mould, desirable 60 ~ 64 HRC; For complex shape and its edge as the main failure form of mold, preferable of 56 ~ 60 HRC, even 54 ~ 58 HRC.