Microstructural Inhomogeneity
Structural inhomogeneity refers to local differences in grain size, phase distribution, or composition within a material. These impair mechanical properties like hardness and toughness.
Physical-chemical mechanism
Structural inhomogeneities arise from uneven cooling or chemical reactions during welding. This leads to different grain sizes and phase distributions within the material.
Metallurgical relevance & risks in welding
These inhomogeneities can cause mechanical weak points like cracks or damage in the weld. They also impair hardness and toughness, which can lead to early failure in service.
Workshop practice & instructions
To minimize structural inhomogeneities, ensure even cooling of the weld. Use suitable shielding gases and protect the weld from chemical influences. In severe cases, post-weld heat treatment like normalizing or tempering can help.