材料期刊网

目的 将低温离子-气体乙炔渗碳应用于AISI 316L奥氏体不锈钢表面硬化处理,同时探讨其硬化处理的最优工艺参数及优化效果.方法 采用离子轰击去除不锈钢表面钝化膜并活化其表面,再进行低温气体乙炔渗碳,实验过程使用脉冲式供气循环处理方式.进行温度梯度实验,寻找渗碳处理的临界温度.并采用正交试验法设计3因素3水平共9组实验,分析气体比例、离子轰击时间、保温压强3个因素对渗碳层硬度和厚度产生的影响,以期得到不锈钢低温离子-气体乙炔渗碳优化工艺.通过对经过最优化工艺处理过后的不锈钢硬化层组织、成分、厚度、硬度、耐磨性、耐蚀性能的研究分析,验证此工艺对AISI 316L奥氏体不锈钢硬化处理的适用性.结果 处理温度为540℃时渗碳层有碳的铬化物析出;离子轰击时间对渗碳层硬度影响最大,保温压强对硬化层厚度影响最明显.在硬化处理温度为520℃,V(H2):V(C2H2)=1:1,渗碳压强为?0.02 Mpa,离子轰击时间为20 min时,316L奥氏体不锈钢离子-气体乙炔渗碳效果最优.经优化工艺处理后不锈钢硬化层厚度达到30μm左右,表面硬度达到838HV0.05,耐蚀性和耐磨性能等都显著提高.结论 低温离子-气体乙炔渗碳硬化处理适用于AISI 316L奥氏体不锈钢,其处理最合适温度为520℃.经优化工艺处理后的不锈钢具有较高的硬度、厚度,良好的硬度梯度,高耐蚀性能及高耐磨性能.

To apply the low temperature ion-gas acetylene carburizing to AISI 316L austenitic stainless steel surface har-dening treatment,and investigate the optimal process parameters and the optimization effectof hardening treatment. In addition to removing the stainless steel surface passivation membrane and ion bombardment activating surface,then the low-temperature gas acetylene carburizing,the experimental process uses pulsed gas circulation processing methods,temperature gradient experi-ment was conducted to find the critical temperature of carburizing process. Experiments were designed using a factorial design based on a L9 orthogonal array.The effect of gas proportion, ion bombardment time and heat preservation pressure on the carbu-rized layer hardness and thickness was analyzed in order to obtain astainless steel ion-gas acetylene carburizing optimization process. Through the research and analysis of stainless steel hardening layer structure, composition, thickness, hardness, wear resistance, corrosion resistance, verify the applicability of the hardening process of AISI 316L austenitic stainless steel. When processing temperature is 540℃ carburized layer with carbon chromium compound precipitation; ion bombardment time has the greatest effect on carburized layer hardness, heat preservation pressure has the greatest impact on the thickness of hardened layer, when carburizing temperature is 520℃,V(H2):V(C2H2)=1:1, carburizing pressure?0.02 MPa, ion bombardment time 20 min, the hardening treatment effect is best.The stainless steel hardening layer thicknessafter optimization process has reached about 30μm, surface hardness is 838HV0.05,corrosionresistance and wear resistance are improved significantly. Conclusion Low temperature ion-gas acetylene carburizing treatment applies to the AISI 316L austenitic stainless steel, which the most suitable temperature is 520℃; stainless steel afteroptimized process treated has high hardness, thickness, good hardness gra-dient, high corrosion resistance and high wear resistance.