| 摘要 |
Method for reducing the segregated seams of a steel which has high mechanical strength and high wear resistance and whose composition comprises by weight: 0.30%≦̸C≦̸1.42%; 0.05%≦̸Si≦̸1.5%; Mn≦̸1.95%; Ni≦̸2.9%; 1.1%≦̸Cr≦̸7.9%; 0.61%≦̸Mo≦̸4.4%; optionally V≦̸1.45%, Nb≦̸1.45%, Ta≦̸1.45% and V+Nb/2+Ta/4≦̸1.45% ; less than 0.1% of boron, less than 0.19% of (S+Se/2+Te/4), less than 0.01% of calcium, less than 0.5% of rare earths, less than 1% of aluminum, less than 1% of copper; the balance being iron and impurities resulting from the production operation. The composition further complies with: 800≦̸D≦̸1150 with D=540(C)0.25+245 (Mo+3 V+1.5 Nb+0.75 Ta)0.30+125 Cr0.20+15.8 Mn+7.4 Ni+18 Si. According to the method, the molybdenum is completely or partially replaced with double the proportion of tungsten so that W>0.21%, and Ti, Zr, C are adjusted so that, after adjustment, Ti+Zr/2≧0.2 W, (Ti+Zr/2)×C≧0.07, Ti+Zr/2≦̸1.49% and D is unchanged at approximately 5%. Steel obtained and method for producing a steel workpiece.
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