Affect cold main factor that make to harden
China precision machining Slice to pare a radius of the blade bluntness to enlarge, to the squeeze of the surface layer metals function to build up, the mold transforms to turn worse, causing the cold and hard to build up.After knife have the knife faces to wear away the aggrandizement, empress the knife face with is process surface of friction turn worse, the mold transform the aggrandizement, causing the cold and hard to build up.
Slice to pare the speed aggrandizement, the knife has to shorten with function time of the work piece, making mold transform expand the depth to let up, the cold and hard layer depth let up.After slicing to pare the speed aggrandizement, slice to pare the heat on a surface of work layer of function time also shorten the joy, will make the cold and hard degree increment.Enter to enlarge for quantity, slice to pare the dint to also enlarge, surface layer the mold of the metals transforms to turn worse, the cold and hard function strengthen.
The mold of a material of work is more big, the cold and hard phenomenon is more serious. (B)The surface layer material gold organizes the variety mutually
China precision machining After slicing to pare the heat to make to be process the temperature of the surface exceeds to change the temperature mutually, the gold of the surface layer metals organizes mutually and will take place the variety.
1. Whet to pare the burn
China precision machining When were attained to change the temperature mutually by a surface of grinder layer temperature above, the variety that the surface layer metals occurrence gold mutually organize, make the surface layer metals strength and degree of hardnesses lower, and the companion contain Residual stress should the dint produce, even appearing the tiny view crack, this kind of phenomenon is called to whet to pare the burn.While whetting to pare the quench steel, possible creation following three kinds of burns:
2.Return to fire burn
China precision machining If whet the temperature of pare the area and did not exceed the quench steel to change the temperature mutually, but have already exceeded MA3 ZHI TI3's change temperature, a surface layer of work metals returns to the fire MA3 ZHI TI3's organization and will change the degree of hardness return to the fire organization(Sorbite and Child's body) lowerly, this kind of burn is called to return to fire burn.
3.The quench burn
If whetted to pare the area temperature to exceed to change the temperature mutually, and cool off the nasty and cold function of the liquid, the surface layer metals take place fire of quench two times, make the surface layer metals appear two times quench Martensite organization, its degree of hardness compare originally return to fire Martensite of high, at its bottom layer, but the gooseflesh compare slowly, appeared the degree of hardness to compare to return to fire at first, Martensite return to the fire organization(Sorbite and Child's body) lowly, this kind of burn is called the quench burn.
4.Back the fire burn
If whetted to pare the area temperature to exceed to change the temperature mutually, but whet to pare the district and did not cool off the liquid into, the surface layer metals will produce to back the fire organization, China precision machining the surface degree of hardness descend nasty play, this kind of burn is called to back the fire burn.
5. The improvement whets the path of pare the burn
Whet to pare hot is a source that results in whet to pare the burn, the past improvement whets to pare the burn from two paths:While reducing to whet to pare the hot real estate to living possibly;Two is an improvement to cool off the condition, make produce the amount of subterranean heat as far as possible little stream into the work piece.