放电电压对纯氮ASPN处理的影响

Effect of Voltage on Active Screen Plasma Nitriding Under Pure Nitrogen

采用高电压、低气压的离子渗氮工艺,利用活性屏离子渗氮(ASPN)技术对合金钢在纯氮气氛下进行离子渗氮处理。对渗氮层的硬度、深度和组织结构等进行了分析研究。结果表明,在纯氮气氛下活性屏离子渗氮处理过程中放电电压起关键作用,只有当直流辉光放电电压高于800 V时,才能进行离子渗氮处理。通过分析用铜片采集的等离子放电空间的粒子发现,放电电压高于800 V时,沉积在铜片表面的粒子是能进行渗氮处理的氮化铁;而放电电压低于800 V时,沉积在铜片表面的粒子主要是氧化铁。

Alloy steel was plasma nitirded under the atmosphere of pure nitrogen using active screen plasma nitriding(ASPN)at high voltage and low pressure. The microstruc-ture, microhardness and depth of the nitrided layers were studied. Experimental results showed that the discharge voltage was the key parameter in the ASPN process. ASPN could take place only when the discharge voltage is higher than 800V. The particles collected on the sheet copper are iron nitride, which are the nitriding species in ASPN only when the voltage is over 800V. But the particles are mostly iron oxide if the voltage is lower than 800V.