奥氏体不锈钢低温渗碳硬化处理后的化学亮化处理

目的研究一种化学方法对经过低温离子渗碳后的奥氏体不锈钢表面进行亮化处理。方法采用酸洗(草酸180~200 g/L,硫脲10~15 g/L,OP-10 10~15 m L/L,温度为70℃,时间为3 min)、除积炭(邻二氯苯610 g/L,水30 g/L,氢氧化钠20 g/L,油酸100 g/L,甲酚240 g/L,处理温度为70℃,在超声波中清洗120 min)、碱洗(氢氧化钠110 g/L,碳酸钠110 g/L,高锰酸钾50 g/L,溶液温度为70℃,在超声波中清洗30 min。)、再酸洗(草酸180~200 g/L,硫脲10~15 g/L,OP-10 10~15 m L/L,溶液温度为70℃,在超声波中清洗1 min)的化学处理过程,对低温离子渗碳硬化处理后的316 L奥氏体不锈钢表面进行亮化处理,并对亮化处理前后硬化层的组织结构、厚度、硬度及耐蚀性能进行比较。结果硬化处理后的不锈钢经过化学亮化处理过程,就可以比较彻底地去除硬化层表面的黑膜,恢复不锈钢的本色。结论化学表面亮化处理后,不锈钢渗硬化层的损失量比较小,去除黑膜后的不锈钢表面表现出很好的耐蚀性能。

Chemical Brightening Treatment of Austenitic Stainless Steel after Low-temperature Plasma Carburizing

Objective To study the method of chemical brightening treatment for austenitic stainless steel after low-temperature plasma carburizing. Methods This paper adopted chemical treatment method to brighten the surface of the carburized 316L austen-ite stainless steel. The chemical treatments included acid-washing(180~200 g/L of oxalic acid,10~15 g/L of thiourea, 10~15 mL/L of OP-10,the temperature was 70 ℃, the time was 3 minutes), removing accumulated carbon (610 g/L of orthodichlorobe-zene,30 g/L of water,20 g/L of sodium hydroxide,100 g/L of oleic acid, 240 g/L of cresol, the temperature was 70℃, ultrosonic cleaning for 120 minutes), alkali-washing (110 g/L of sodium hydroxide,110 g/L of sodium carbonate,50 g/L of potassium per-manganate, the temperature was 70 ℃, ultrosonic cleaning for 30 minutes) and acid-washing (180~200 g/L of oxalic acid,10~15 g/L of thiourea, 10~15 mL/L of OP-10, the temperature was 70 ℃, ultrosonic cleaning for 1 minute). Austenite stainless steel after low-temperature plasma surface hardening was brightened by means of chemical method. The thickness, microstructure,microhardness and corrosion resistance of the samples before and after brightening were compared. Results Experimental results showed that the chemical brightening could restore its original color of the hardened stainless steel. Conclusion The thickness and surface hardness of the hardened layer decreased slightly after chemical brightening. However, the corrosion-resistant property was much better than that of the sample before chemical brightening.