Shrinkage
Shrinkage is the shortening of components during cooling when the material contracts. This must be considered in the design.
Physicochemical mechanism of action
When metals cool, the crystal lattice shrinks and the atoms move closer together, causing volume contraction. This process is especially strong with rapid cooling or with materials that have a high melting point.
Metallurgical relevance & risks when welding
Shrinkage can cause stresses in the component that can lead to cracks or deformation. If shrinkage is not considered in the design, stress zones develop that put the material under pressure and can distort it. This is especially dangerous with thick components or when the material contracts strongly.
Workshop practice & instructions
To minimize shrinkage, control the cooling process. Use slow cooling methods like thermal insulation or cooling banks. For thin components or when stress capability is low, shrinkage can be reduced by cavities or compensating weld seams. When planning components, it is important to consider the shrinkage rate of the material used and incorporate appropriate measures into the design.