TY - JOUR A1 - El-Batahgy, A.M. A1 - Gumenyuk, Andrey A1 - Gook, S. A1 - Rethmeier, Michael T1 - Comparison between GTA and laser beam welding of 9%Ni steel for critical cryogenic applications N2 - IncomparisonwithGTAweldedjoints,highertensilestrengthcomparabletothatofthebasemetalwasobtained for laser beam welded joints due to fine martensitic microstructure. Impact fracture toughness values with much lower mismatching were obtained for laser beam welded joints due to similarity in the microstructures of its weld metal and HAZ. In this case, the lower impact fracture toughness obtained (1.37J/mm2) was much higher than that of the GTA welded joints (0.78J/mm2), which was very close to the specified minimum value (≥0.75J/mm2). In contrast to other research works, the overall tensile and impact properties are influenced not only by the fusion zone microstructure but also by the size of its hardened area as well as the degree of its mechanical mismatching, as a function of the welding process. A better combination of tensile strength and impact toughness of the concerned steel welded joints is assured by autogenous laser beam welding process. KW - Impact absorbed energy KW - 9%Ni steel KW - GTAW KW - Laser beam welding KW - Fusion zone size KW - Microstructure Tensile strength PY - 2018 U6 - https://doi.org/10.1016/j.jmatprotec.2018.05.023 SN - 0924-0136 IS - 261 SP - 193 EP - 201 PB - Elsevier AN - OPUS4-45776 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -