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What is High-Speed Steel? |
| Author : Date : 2011-10-10 19:01:38 |
What is High-Speed Steel?
Actually the performance of high-speed steel is not advanced ,but they have been processed into various cutting tools and taken near half of the market due to its good stability and machinality .The traditional common grade is W18Cr4V and W6Mo5Cr4V2.In W series high-speed steels ,in addition to MC,M2C,M23C ,the M6C is the main carbon substance that is Fe3W3C and Fe4W2C.On the contrary ,in W-Mo series high-speed steel ,M6C is Fe3(W,Mo)3C.In all the high-speed steels ,the Cr composition with function to optimize its hardenability by forming of Cr23C6 only takes 3.5%~4.5% of the total content. With the increase of V element ,its wear-resistance and fragileness also are increased ,meanwhile it is very hard to sharp it. The Vanadium carbide is VC and V4C3,the steel with 1%~2% V is very widely used, meanwhile ,it is rarely used with V>3% and unavailable to be processed into complicated-profile parts. If the Cobalt element added ,we can make super-hard high-speed steel,as Cobalt does not form a carbide, but it is helpful to increase quenching temperature, enhance secondary harden effect, and increase high-temperature hardness .The grade M42(110W1.5Mo9.5Cr4VCo8) and HSP-15(W9Mo3Cr4VCo10) are the high performance high-speed steel with high cobalt in America and Sweden respectively.Cobalt is very expensive in China due to lack of this resource ,so we have developed super-hard high-speed steel with very few or free cobalt .Co5Si(W12Mo3Cr4V3Co5Si) is the few cobalt one ,the newly developed Co3N(W12Mo3Cr4VCo3N) one with good performance is also the few cobalt .The Al2O3 and AlN are formed by element Aluminum in steel,which take the function of strengthen its structure and avoid dislocation so as to improve the materials hardness and T.R.S .China has made great contribution in the filed to develop high-speed steel with free or few cobalt . |
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