Precipitation Behaviour and Its Strengthening Effect of Maraging Steel in Laser Cladding Remanufacturing

Abstract

Laser hot-wire cladding is one of the major remanufacturing processes used to repair damaged compressor impellers. The strength of cladding layer and heat affected zone (HAZ) is essential to the functionality and reliability of repaired parts. This paper makes a qualitative explanation of strength variation by analyzing the microstructure of the substrate. A thermal simulation experiment was conducted to investigate the effect of aging temperature on the strength of the substrate. Results showed that the strength trend in the cladding layer and HAZ varied with respect to the aging temperature as a result of precipitation behavior. Heat treatment temperature was divided into three intervals depending on its effect. Further, the tip temperature of substrate solid solution was found out to be 500 °C. Precipitates coarsening and dissolution in aging state substrate led to heat affected zone softening.