The grain size has an important influence on the high temperature ductility and on the reheat cracking susceptibility. A ________ grain size results in _______ ductile heat affected zones, making the material more susceptible to reheat cracking.
The grain size has an important influence on the high temperature ductility and on the reheat cracking susceptibility. A ________ grain size results in _______ ductile heat affected zones, making the material more susceptible to reheat cracking.
A large grain size results in more ductile heat affected zones, making the material more susceptible to reheat cracking. Larger grains generally have fewer boundaries, which can lead to lower strength at high temperatures and increased ductility, thereby reducing the material's resistance to cracking during reheating.
Large grain size means less total grain boundary volume to accommodate the creep strain, i.e. the creep strain is concentrated in a relatively small grain boundary volume