As-cast texture
The cast texture is the primary structure that forms directly as the weld pool cools. It often shows columnar or coarse-grained regions.
Physical-Chemical Mechanism of Action
Casting texture forms during rapid cooling of molten metal in solidification. The quickly cooling surfaces form grain structures, while deeper areas cool slower and form larger grains.
Metallurgical Relevance & Risks in Welding
Uneven casting texture can lead to stress buildup, especially when the material cools at different rates. This can cause cracks and hot cracking. Additionally, texture affects mechanical properties like strength and ductility of the weld.
Workshop Practice & Action Guidelines
To ensure a homogeneous casting texture, it's important that the metal cools evenly. This can be achieved by proper selection of the melt pool and cooling techniques. For heavy steels or in high-stress areas, controlled cooling with a water bath or gas cooling treatment should be applied.