GMA-WELDED STE-885 STEEL WHEN SUBJECTED T O STATIC, DYNAMIC AND CYCLIC LOADING

Examined was the behaviour of a GMA multi-pass welded 25 mm plate of h igh-tensile weldable StE 585 structural steel subjected to static, cyc lic and dynamic loading. It is possible, by using the model of thermal ly activated flow, to describe the behaviour of the parent metal when subjected to tensile loading at temperatures ranging from -178 degrees C to +150 degrees C and at loading rates from 10(-4) to 135 1/s. The static and dynamic fracture mechanics parameters fall into the categor y where the strength is dependent on the crack initiation resistance o f quenched and tempered structural steels. The weld metal displays the lowest crack initiation parameters in this respect. The cyclic stress -strain curves can be classified according to the tensile strength and confirm the familiar cyclic softening tendency. There is little diffe rence in the Manson-Coffin curves of the parent metal, heat-affected z one and weld metal. Cyclic crack growth curves, determined for various stress ratios, permit fracture-mechanical calculations of the residua l life.