Effect of heat treatment on plastic deformation inhomogeneity of laser cladding additively manufactured metal composite

Abstract

The inhomogeneity of plastic deformation of laser cladding additively manufactured steel composites from low-carbon steel ASTM A414 grade A and stainless steel AISI 304 has been studied. The uniaxial tensile tests were carried out on flat samples with a thickness of 8 mm at a constant rate at room temperature after laser cladding and after six hours of heat treatment of specimens up to 900°C. The phase composition of the bimetal components was determined via X-ray diffraction. The effect of heat treatment conditions on the microhardness and plastic flow inhomogeneity near the bimetal junction zone has been established. The degree of plastic deformation inhomogeneity of different layers was quantitatively assessed using the coefficient of variation of local strains has been investigated via digital speckle correlation method. After laser cladding, the difference between the deformation inhomogeneities of the border zones near stainless and carbon steels was almost two times. The deformation inhomogeneity in the transition zone was shown to differ from those of the base layers, which affected the properties of bimetal products. The effect of structural heterogeneity near the interface of layers on the local strain distributions in the bimetal was discussed in present study.