Residual stress distribution in laser alloying zone with FeCSiB powder

Laser alloying surface of spheroidal graphite iron and plain carbon steel improve the wear resistance of many industrial components. But the distribution of residual stress in the laser alloying zone and its adjacent area, that may affect the wear performance and the sensitivity of fatigue and fracture, has not been investigated systematically. In this paper the stresses distribution on the spheroidal graphite iron surface of the laser alloying zone with FeCSiB powder has been measured by X-ray diffraction technique. The results of XRD and optical microscope quantitative analysis show that the main phases of the laser alloying zone are Fe₃C and α-Fe (plus martensite) with approximate the same volume fraction. The residual stress state of the two phases has been analyzed. It is found that laser alloying zone (LAZ) is subjected to high tensile stresses while the area surround LAZ is subjected to compressive stresses.