Relaxation Rotation during Martensitic Transformation and Scattering of the Martensite Texture

In the crystallographic theory of martensitic transformation, a new characteristic of martensitic transformation appears—a relaxation rotation, which was not in the generally accepted phenomenological theory of martensitic transformations. The relaxation rotation is necessary to obtain an invariant plane. The calculated angle of relaxation rotation for iron alloys with nonthermoelastic martensite is 1.75–1.85 degrees; for thermoelastic Geisler alloys with multilayer martensite, it is 0.19–0.36 degrees. The relaxation rotation leads to scattering of the texture of martensite. The scattering angles of single X-ray reflections of martensite in different alloys were measured, and it was found that the scattering angle corresponds to the angle of relaxation rotation. This result shows that the crystallographic theory of martensitic transformation describes the real mechanism of martensitic transformation.