2014 年 100 巻 10 号 p. 1281-1288
Numerical simulation of microscopic stress distribution in weld metal considering anisotropy of crystal orientation observed in weld solidification microstructure was performed. A finite element model of columnar grain aggregate was generated and anisotropic crystal orientation considering the characteristics of austenitic stainless steel weld metal was defined. Microscopic stress distribution occurred in the columnar grain model under tensile loading was investigated by a series of numerical simulations incorporating crystal plasticity theory.
From the case where tensile displacement was applied perpendicular to the longitudinal direction of columnar grains, the following results were obtained: The maximum microscopic stress occurred in the columnar grain model was almost independent of the angle between the longitudinal direction of columnar grains and <1 0 0> direction, and it was 1.59 times to 1.75 times higher compared to the macroscopically applied stress. From the case where tensile displacement was applied parallel to the longitudinal direction of columnar grains, the following results were obtained: The maximum microscopic stress occurred in the columnar grain model increased with increasing angle between the longitudinal direction of columnar grains and <1 0 0> direction. The above two major simulation results showed that higher microscopic stress compared to the macroscopically applied stress could be observed when tensile load was applied perpendicular to the longitudinal direction of columnar grains.
