Steel with high mechanical strength and wear resistance

Abstract

The invention relates to a steel with high mechanical strength and wear resistance. More specifically, the invention relates to a method of reducing the segregated veins of a steel having high mechanical strength, high wear resistance and the following weight composition: 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% borium, 0.19% (S + Se/2 + Te/4), 0.01% calcium, 0.5% rare earths, 1% aluminium, 1 %copper; the remainder being iron and impurities resulting from the production thereof. The composition also comprises: 800 <= D <= 1150, where D = 540(C)<0.25> + 245 (Mo + 3 V + 1.5 Nb + 0.75 Ta)<0.30> + 125 Cr<0.20 >+ 15.8 Mn + 7.4 Ni + 18 Si. According to the invention, all or part of the molydenum is replaced by a double proportion of tungsten, such that W >= 0.21%, and Ti, Zr, C are adjusted so that, after said adjustment, Ti + Zr/2 >= 0.2 W, (Ti + Zr/2) * C >= 0.07, Ti + Zr/2 <= 1.49 % and D is unchanged at 5 %. The invention also relates to the steel obtained and to a method of producing a steel part.

Description

technical field [0001] The present invention relates to steels with high mechanical strength and high wear resistance. Background technique [0002] In a large number of industries steels with high wear resistance are used. These are steels, for example, that are used to make components for mining equipment and must be wear-resistant. They are also the steels used to make tools for cold forming or forming metal workpieces at moderate temperatures, and these steels must wear wear due to metal-to-metal type friction. For these machining tool applications, the steel must at least retain good properties despite being heated to temperatures which may reach 500°C or 600°C. [0003] In addition to wear resistance, the steels considered here must also have suitable properties in order to be able to be machined or welded. Finally, they must be able to withstand shocks or severe loads. [0004] In general, in order to obtain all the desired properties, it i...

AI Technical Summary

Problems solved by technology

[0006] However, high levels of strong carbide-forming elements, such as molybdenum and vanadium, must be present to cause sufficiently hardened and temperature-stable secondary precipitates, and this does have the disadvantage of leading to the formation of seams in those Elemental neutralization is highly segregated in carbon and is therefore very hard and very brittle

Those segregated seams make machining or welding difficult

Furthermore, they constitute frangible zones, albeit localized, which can considerably reduce the impact resistance and the resistance to severe bending loads of the workpiece

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