subject: Hot Work Die Steel, And The Difference Between Cold-working Die Steel - Tool Steel - Metal Industry [print this page] 1, cold Mold Steel Cold Mold Washed and used for the manufacturing of steel mold (punching die blanking, trimming mode, Drift , Scissors ), Cold heading dies and cold extrusion, bending mode and Wire Drawing Die Etc.
1. Cold Work Die Steel working conditions and performance requirements
Cold work die steel at work. As the deformation resistance of materials to be processed relatively large part of the mold under great pressure of work, bending strength, impact and friction. Therefore, the normal retirement Cold mold usually causes wear. Also due to fracture, collapse strength and deformation tolerance and early failure.
Cold steel mold steel, compared with cutting tools. There are many things in common. Asked Die has a high hardness and wear resistance, high bending strength and toughness sufficient to ensure the smooth progress of the stamping process, the difference is that I die shape and increase process complexity. And the large area of friction. Wear the possibility of Great. so grinding up the difficulties. Therefore requires a higher wear resistance to withstand the impulse of the die pressure. Also, because complex shapes are prone to stress concentration, it requires a higher toughness; die size of large, complex shape. Therefore, the higher hardenability requirements, small deformation and crack orientation. In short, cold die steel hardenability, wear resistance and toughness and other requirements to be higher than that of steel cutting tools. The mandatory terms in red are required low or virtually no requirements (as is the cold forming), so accordingly suitable for the formation of a number of cold-working die made of steel used, for example, the development of a high wear resistance, micro-deformation and high resilience cold-working die steel such as cold-working die steel. The following combination of the steel used further.
2. Steel options Usually followed by cold conditions of use molds, steel can be divided into the following four cases selected:
(1) small size, the shape of a simple, light load of cold mold. For example. Small punch, scissors and other cutting off the plate can choose T7A, T8A, T10A, T12A and other carbon Tool Steel. The advantages of this type of steel; machinability is good, cheap, easy source. But the disadvantages are: low hardenability, wear resistance is poor, large deformation hardening. Therefore, only suitable for the manufacture of some small size, the shape of a simple, light load of tools and hardened layer is not required to maintain a high toughness of deep and cold-like mold.
(2) large size, complex shape, light load of cold mold. Commonly used steel have 9SiCr, CrWMn, GCr15 and low-alloy cutting tools 9Mn2V steel. These steel quenching in oil up to 40mm diameter or more generally. One recent development 9Mn2V Steel is a free country Cr of Cold Work Die Steel. Can replace or partially replace the steel with Cr.
9Mn2V uneven carbon steel and quenched steel cracking tendency than CrWMn smaller than 9SiCr steel decarburization bias is small, and hardenability than carbon tool steel major. The price is about 30 higher than the latter % so it is a worth to promote the use of steel.
But 9Mn2V steel, there are some drawbacks such as the impact toughness is not high, found in use in the production of the phenomenon of fragmentation. Also tempering poor stability, tempering temperature normally does not exceed 180 when the bending and tempering at 200 strength and toughness appeared low.
9Mn2V steel in nitrate, heat oil cooling capacity of quenching media moderate quenching. For some deformation and hardness requirements without demanding a high mold, can be used austenitic austempering.
(3) large size, complex shape heavy duty cold mold. To be used in the alloy or high alloy steel. If Cr12Mo, Crl2MoV, Cr6WVCr4W2MoV, etc. There is also a selected high speed steel.
Recent years, high-speed steel made cold mold growing tendency to increase Pakistan, it should be noted that at this time is no longer unique to the use of high red hardness of steel strength. And with its high hardenability and high resistance grindability.
