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

Abstract:

QPQ salt bath treatment of a certain type aviation piston engine ring was conducted by nitriding (570°C, 180 min), followed by the post-oxidation process (400°C, 20 min), polishing, the second post-oxidation (370°C, 20 min). Characterization of modified surface layers was made by means of optical microscopy, micro-hardness test, corrosion and wear resistance test. The results showed the formation of a very thin oxide layer during post-oxidation on the top of the black nitrides compound layer formed during nitriding. The maximum micro-hardness value of 592 HV was obtained after nitriding at 570°C for 180 min, which was nearly twice higher than that of the untreated sample. The wear resistance of ring could be significantly improved by QPQ complex salt bath treatment, which is almost 5 times higher than that of the untreated sample.

• Periodical: Applied Mechanics and Materials (Volume 751)
• Pages: 26-29
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.751.26
• Online since: April 2015
• Authors: Jun Wen Lu*, Qian Ying Wang, Bo Zheng
• Keywords: Aviation Piston Engine Ring, Micro-Hardness, Microstructure of Layer, QPQ Treatment, Wear Resistance

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