CNO^-浓度对W18Cr4V钢液体硫氮碳共渗速度及其组织性能的影响

Effect of CNO^- Concentration in Salt Bath on Sulpho-Nitrocarburizing Rate, Microstructure and Properties of W18Cr4V Steel

叙述了W18Cr4V高速钢在无公害液体S、N、C共渗过程中,CNO-浓度高低对渗层深度、组织及性能的影响。试验结果表明,CNO-浓度在26%~37%范围内时,共渗速度随CNO-浓度的增加而加快,渗层硬度随CNO-浓度的升高而增加,渗层组织为氮的扩散层,而没有氮的化合物层;将共渗与回火复合为一道工序后,既节省了时间,又提高了零件的表面硬度,使用寿命比原来提高一倍。

Effect of CNO^- concentration on the coating rate,microstructure and properties of sulpho-nitrocarburizing in a salt bath of W18Cr4V steel was investigated. The experimental results show that coating rate and microhardness increase with the increase of CNO^- concentration in the sah bath. The microstructure consists of a nitrogen diffusion zone without white layer treated with the rang of CNO^- concentration 26% -37%. When the sulpho-nitrocarburizing combined with tempering in the same salt bath,the heat treatment time can be saved,the surface hardness is increased and the servicelife of the dies or tools can be increased by two times.