| 摘要 |
PCT No. PCT/SE98/00334 Sec. 371 Date Jun. 17, 1999 Sec. 102(e) Date Jun. 17, 1999 PCT Filed Feb. 25, 1998 PCT Pub. No. WO98/40180 PCT Pub. Date Sep. 17, 1998The invention relates to a steel having the following alloy composition in weight-%: 1.4-1.6 (C+N), max. 0.6 Mn, max. 1.2 Si, 3.5-4.3 Cr, 1.5-3 Mo, 1.5-3 W, wherein 6<Weq<9, and Weq=% W+2x% Mo, 3.5-4.5 V, max. 0.3 S, max. 0.3 Cu, max. 1 Co, a total amount of max. 1.0 of Nb+Ta+Ti+Zr+Al, a total amount of 0.5 of other elements, including impurities and accessory elements in normal amounts, balance iron, and with a microstructure substantially consisting of a martensitic matrix and in the matrix 2-15, preferably 5-10 volume-% undissolved hard products having the particle size 0.1-3 mu m, said hard products being of MX-type, where M is V and X is C and/or N, wherein 40-60% of the C and N content of the alloy is bound to vanadium as carbides and/or as carbo-nitrides, and a functional amount of hard products precipitated in the martensitic matrix after solution heat treatment of the steel at a temperature between 1000 and 1225 DEG C. and tempering at least twice for at least 0.5 h at a temperature between 190 and 580 DEG C., and the use of the steel for tools for forming and/or cutting operations. |
