| The ductility dip cracking sensitivities of four kinds self-made Inconel690 electrode filler metals were valued using STF(Strain-to-Fracture) and hot ductility experiments, which was the first time to value the ductility dip cracking sensitivity for Ni-based alloys electrode filler metal on domestic and abroad.In this paper, The influences of the Nb and Mn on the ductility dip cracking sensitivity for Inconel690 electrode filler metal were studied. The results showed that Nb existed in grain boundary by the form of carbide, and then inhibited the sliding of grain boundary, decreased the ductility dip cracking sensitivity, but melting phenomena occurred when it exceeded a certain amount, so 1.73wt.% was optimum experimental value; Mn existed in grain boundary by the form of oxide, and then inhibited the sliding of grain boundary, decreased the ductility dip cracking sensitivity.The ductility dip cracking of Inconel690 filler metal is a kind of high temperature solid phenomenon, the mechanism is: grain boundary is relatively weaken at high temperature, grain boundary occurs to slip under the outside force, which cause the strain concentration at he grain boundary, then crack appears when local strain exceeds the distortion ability of the material.According to the above mentioned results, the developed Inconel690... |
