非调质钢表面硬化处理工艺

Trial Surface-Hardening Processes for Non-Quenched and Tempered Steels

试验用非调质钢为F35MnV、F38MnVS、F40MnVS、F45MnVS及F49MnVS铁素体-珠光体钢和F12Mn2VBS贝氏体钢。对这些钢进行了表面硬化处理试验。结果表明,铁素体-珠光体型非调质钢可采用气体渗氮、离子渗氮和气体氮碳共渗以提高其表面硬度和耐磨性,但贝氏体非调质钢氮碳共渗处理后,其冲击韧度从46.7 J降低到了35.0 J,故不宜采用该工艺进行表面硬化。此外,F40MnVS钢的高频感应淬硬层表面硬度和硬化层深度与45钢的基本相同,经渗氮处理的F35MnV和F40MnVS钢渗层的化合物层比40Cr、45和38CrMoAlA钢的薄,而扩散层较厚者厚,表面硬度比40Cr、45钢高,比38CrMoAlA钢低。经气体氮碳共渗的非调质钢具有良好的综合力学性能。

Non-quenched and tempered steels, including ferrite-pearlite steels such as F35MnV, F38MnVS, F40MnVS,F45MnVS and F49MnVS steels, and F12Mn2VBS beinitic steel, were subjected to trial surface- hardening treatments. The results indicated that the non-quenched and tempered ferrite-pearlite steels were suited to be gas nitrided, ion-nitrided, and gas nitrocarburized for the purpose of increasing their surface hardness and wear resistance, however, the non-quenched and tempered bainitic steel showed decrease from 46.7 J to 35.0 J in impact toughness after nitrocarburizing, thus being inadvisable to be surface-hardened by this procedure. Furthermore, F40MnVS and 45 steels after being high-frequency induction hardened exhibited roughly same surface hardness and case depth. After being gas nitrided, both F35MnV and F40MnVS steel possessed thinner compound layer and thicker diffusion layer as compared with 40 Cr and 45 steels, higher surface hardness as compared with 40Cr and 45 steels, and lower surface hardness as compared with 38CrMoAlA steel. The non-quenched and tempered steels were possessed of good mechanical properties after gas nitrocarburizing.