TY - JOUR T1 - Microstructure and Mechanical Properties of DC-LSND Double Cooling on A-36 Steel Welded Joints AU - Wibowo, H. AU - Ilman, M.N. AU - Iswanto, P.T. JO - Journal of Engineering and Applied Sciences VL - 13 IS - 17 SP - 7341 EP - 7347 PY - 2018 DA - 2001/08/19 SN - 1816-949x DO - jeasci.2018.7341.7347 UR - https://makhillpublications.co/view-article.php?doi=jeasci.2018.7341.7347 KW - DC-LSND double cooling KW -welded joints KW -distortion KW -liquid nitrogen KW -microstructure KW -refined AB - 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. ER -