Effect of tool pin length on interfacial behaviors and mechanical properties of friction stir-welded lap joints of 430/304 stainless steels

In this study, the effect of tool pin length on friction stir lap welding 430 and 304 stainless steels has been investigated. The thermal history interface was measured by thermocouple. interfacial macro- micro-structures under different lengths were analyzed via optical microscope scanning electron microscope. Also, tensile shear tests carried out to evaluate strength joint. results show that increasing from 0.5 1.3 mm increases peak temperature interface, which a significant diffusion layer formation hook geometry. fracture mode joints shifts with increase insertion depth. When is 1.0 mm, i.e., slight penetration into plate, joint presents maximum failure load 2.86 kN. findings reveal effective top plate thickness (Teff) used describe geometry an important factor determining mode.