Hardening distortion
Hardness distortion is an uneven hardness development in a part from uneven heating and cooling during hardening. It leads to non-uniform hardness and can cause mechanical stress and failure.
Physical-Chemical Mechanism
Hardness distortion happens when a metal part isn't heated or cooled evenly during hardening. This can come from uneven distance to the heat source or irregular cooling. Uneven heating and cooling cause different hardness levels in the part.
Metallurgical Relevance & Welding Risks
Uneven hardness can cause mechanical stress and failure. High-hardness spots may crack, while soft areas deform. This can lead to fractures, ruin weld zones, or shorten part life.
Workshop Practice & Action Points
To minimize distortion, heat and cool the part evenly. Use quench water with a stable temperature. Cool slowly and controlled for uniform hardness. For complex parts, use special cooling programs or fixtures.