Almen Arch Height
The Almen strip arc height is the measure of the curvature of a test strip after shot peening. It indicates how deformable the steel is and serves to adjust peening processes.
Physical-Chemical Mechanism of Action
The Almen strip arc height is determined by the deformation of a strip under stress. During shot peening (e.g., in laser welding), a curvature develops in the strip, and its height is measured.
Metallurgical Relevance & Welding Risks
An excessively high arc height indicates excessive deformability or insufficient hardness. This can lead to cracks and brittleness. An excessively low arc height indicates a too hard, non-deformable material structure, leading to stresses and damage during welding.
Workshop Practice & Instructions
The Almen strip arc height should be between 0.2 mm and 1.5 mm, depending on the chosen material. For a typical laser welding process, the arc height is about 0.8 mm. Monitor the temperature and stress during shot peening to achieve optimal arc height.