Microstructure and residual stress analysis of explosion cladded inconel 625 and ASME SA516-70 carbon steel bimetal plates

Abstract

In the present work the explosion welded joint produced between an Inconel 625 alloy and ASTM A516-70 carbon steel plates was investigated. After welding, the cladded plates were submitted to stress relief annealing at 600 °C for 3 h. The cross section of the cladded plates was examined in both as welded and heat treated conditions by optical microscopy and scanning electron microscopy. The hardness profile across the cladded interface was measured and the residual stress state created as a consequence of the explosion welding process was determined by X-ray diffraction. The experimental results showed that the Inconel 625 alloy adhered well to the ASTM SA516-70 steel, demonstrating the viability of the explosion cladding process for producing bimetal plates of the mentioned alloys. In the as welded condition, metallography analysis indicated severe plastic deformation close to the cladded interface and a wavy morphology characteristic of high bond strength. Elevated tensile residual stresses were created as a result of the welding process and considerable stress relaxation was attained by application of the proposed heat treatment. © (2014) Trans Tech Publications, Switzerland.