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本文对3Cr2W8V钢的气体渗氮、离子渗氮、气体软氮化等工艺进行了对比研究。通过金相检验、显微硬度测定、X射线衍射相结构分析,结合耐磨和冲击等试验,初步探明了上述工艺对渗层的影响。研究表明,气体渗氮工艺时间长,表层脆性大,易出现开裂及剥落现象。离子渗氮工艺存在加热温度不均匀的弱点,不宜用于形状复杂、深孔的模具。气体软氮化工艺可弥补上述二工艺不足,且表层硬度、耐磨性较高,可有效地减少磨损及粘模,提高工件光洁度。此外气体软氮化还具有生产周期短,易返修,设备简单,操作方便等特点。较适用于3Cr2W8V钢制模具的表面强化。研究还表明,采用50%甲醇气与50%氮气,加热温度580℃,保温时间4.5h随后油冷的气体软氮化工艺,可得到满意结果。
In this paper, 3Cr2W8V steel gas nitriding, ion nitriding, gas nitrocarburizing and other processes were compared. Through the metallographic examination, the microhardness measurement, the X-ray diffraction phase structure analysis, combined with the wear resistance and the impact test, it is preliminary to ascertain the influence of the above process on the coating. Research shows that gas nitriding process for a long time, surface brittleness, prone to cracking and spalling phenomenon. Ionic nitriding process exists the heating temperature is not uniform weaknesses, should not be used for complex shape, deep hole mold. Gas nitrocarburizing process can make up for the above two processes, and the surface hardness, high wear resistance, which can effectively reduce the wear and sticky mold, improve workpiece finish. In addition, gas nitrocarburizing also has short production cycle, easy rework, simple equipment, easy operation and so on. More suitable for 3Cr2W8V steel mold surface hardening. The research also shows that satisfactory results can be obtained by gas nitrocarburizing with 50% methanol gas and 50% nitrogen, heating temperature 580 ℃, holding time 4.5h and then oil cooling.