Weldability of Fe-36%Ni Alloy (Report VI) : Further Investigation on Mechanism of Reheat Hot Cracking in Weld Metal(Materials, Metallurgy & Weldability)

概要

論文の詳細を見る
Stress concentrator, such as grain-boundary precipitates, grain-boundary ledges and/or serrated grain-boundary, necessary for cavity formation by grain-boundary sliding was studied to complete the mechanism of the reheat hot cracking in weld metal of Fe-36%Ni alloy Invar. Main conclusions obtained are as follows: (1) The temperature dependencies of ductility and wavy feature of intergranular fracture surface were correlated well to the densities of precipitates on intergranular fracture surface and the serrated grain-boundary, respectively. (2) Thus, it was considered that the cavities were formed by the cooperation of the grain-boundary precipitates and the serrated grain-boundaries. (3) Grain-boundary precipitation was promoted near the intersection with dendritic subboundaries by the solidification microsegregation, and this is one of the reason why the weld metal is very sensitive to the cracking comparing HAZ. (4) Comprehensive model are proposed for the mechanism of reheat hot cracking.
大阪大学の論文