中碳碳素钢的液体渗氮

Liquid Nitriding Process for Ordinary Medium Carbon Steel

采用QPQ技术对45钢进行表面改性处理,探讨了不同工艺参数对45钢的抗蚀性的影响。研究结果表明,45钢在560℃液体渗氮120 min后,硬度峰值约为600 HV,比基体高2倍多。工件经QPQ工艺处理后渗层结构由表及里为致密的氧化膜、疏松层和致密渗氮层,具有较好的抗腐蚀性能。45钢试样经560℃、90 min渗氮随后氧化20 min后,抗中性盐雾腐蚀时间为200 h。若再经抛光和350℃二次氧化处理,其抗中性盐雾腐蚀时间达到了250 h以上。

45 steel was surface modified by QPQ technology. The effect of process parameters on the resistance to corrosion of 45 steel was explored. The experimental results indicate that the maximum hardness of 45 steel liquidnitrided at 560 ℃ for 120 min will be 600 HV and two times higher than that of matrix. The case of parts subjeted to QPQ processing consists of dense oxide film as well as loose and dense nitrided areas from the outside to the inside, possessing a better anticorrosion. The 45 steel specimen liquid-nitrided at 560 ℃ for 90 min and subsequently oxidized for 20 min can withstand neutral salt spray corrosion for 200 h. If the specimen is again polished and reoxidized at 350 ℃ it can withstand neutral salt spray corrosion for 250 h and above.