Investigating the Effects of Heat Treatment in the Microstructure and Metallurgical Properties of the Explosive Welding of 304 Stainless Steel and CK45 Carbon Steel

In this research,the effects of heat treatment on microstructure and mechanical properties of explosively bonded 304 stainless steel-Ck45 Carbon steel with constant explosive ratio and different standoff were investigated. Samples were heat treated in 2500C and 3500C for 2 and 4 hours in the furnace, and optical microscopy, electron microscopy, micro hardness test and tensile shear test were carried out on samples. Diffusion of iron, chromium, manganese elements and chemical composition of local melted zone were investigated by EDS analysis. The results showed that by increasing standoff from 4 to 5 mm, impact kinetic energy was increased and interface was deformed under severe plastic deformation. Metallography study showed that wavy-vortex interface was created by increasing the standoff. Heat treatment at 3500C for 2 h, increased the thickness of interface intermettallics compounds. Hardness in samples with 4- 5mm standoff was decreased by heat treating 3500C , 2 hr from 270.11 to 171.00 Hv and 279.00 to 195.00 Hv respectively. Strength of samples also decreased from 449.21 MPa to 370.81 MPa and 510.57 to 433.83 MPa respectively. The hardness and strength changes are due to a changes in intermetallics thickness and grain growth phenomenon.