H. Wibowo, M.N. Ilman, P.T. Iswanto
The use of certain welding techniques to reduce distortion in the welding of thin plates to the hull of a ship has become one of the most recent objects of research. One of the alternative welding techniques developed is called the DC-LSND (Dynamically Controlled Low Stress No-Distortion) technique. The investigation concerned here was aimed at studying the effect of DC-LSND double cooling on the distortion, microstructure and mechanical properties in A36 steel welded joints. The DC-LSND double cooling treatments were performed by cooling the HAZ (Heat Affected Zone) behind the welding torch by using cryogenic liquid nitrogen. A sequence of tests was carried out involving distortion measurement, microstructure examination, hardness measurement and tensile testing in combination with SEM fractography. The results showed that DC-LSND double cooling treatments affected transverse distortion significantly. The strength of the welded joint was improved by the DC-LSND double cooling treatments, based on the results of the tensile testing and the hardness. The microstructure was also refined by increasing the acicular ferrite phase. © Medwell Journals, 2018.
Department of Mechanical and Industrial Engineering, Gadjah Mada University, Yogyakarta, Indonesia; Department of Mechanical Engineering Education, Yogyakarta State University, Yogyakarta, Indonesia
