QPQ处理对某型航空活塞发动机活塞涨圈组织与性能的影响

Influence of QPQ Salt Bath Composite Processing on Microstructure and Property of Certain Type Aviation Piston Engine Ring

对某型航空活塞发动机涨圈进行了QPQ处理,首先执行570℃×180 min的渗氮处理,之后进行了400℃×20 min的氧化处理,抛光后又进行了370℃×20 min的二次氧化。通过光学显微镜、显微硬度计以及摩擦磨损试验机研究了经过QPQ处理的涨圈表面特性。结果表明,经QPQ处理后的涨圈表面由外向内形成了氧化膜、渗氮层以及扩散层。经QPQ处理的涨圈表面最大硬度为592 HV,比未处理前增加了近1倍,其耐磨性比未处理前提高了近5倍。

QPQ salt bath treatment of a certain type aviation piston engine ring was conducted by nitriding at 570 ℃ for 180 min, followed by the post-oxidation process at 400 ℃ for 20 min. After polishing, the second post-oxidation was carried out at 370 ℃ for 20 min）. Characterization of modified surface layer was studied by OM, micro-hardness test, corrosion and wear resistance test. The results show the formation of a very thin oxide layer during post-oxidation on the top of the black nitrides compound layer is formed during nitriding. The maximum micro-hardness value of 592 HV is obtained afar nitriding at 570 ℃ for 180 min, which is nearly 1 times higher than that of the untreated sample. The wear resistance of ring can be significantly improved by QPQ complex salt bath treatment, which is almost 5 times higher than that of the untreated sample.