EBSD investigation of texture and microstructure evolution in dissimilar supermatinsitic /duplex stainless steel weld joint
The Crystallographic texture, microstructure and phase transformation are studied in a 13Cr supermartensitic stainless steel. The analysis has been performed through a coupling of the results coming from dilatometry, light optical microscopy, Electron Backscattered Diffraction (EBSD) and hardness measurements. Dilatometry test was used to determine phase transformation temperatures. Preliminary characterization conducted using light optical microscopy revealed the characteristic lath martensite microstructure usually observed in low-carbon steels consisting of prior austenite grains divided into a three-level hierarchy in terms of morphology: packet, block and lath. Detailed texture and microstructure investigation carried out using EBSD determined the crystallographic texture, misorientation angles as well as misorientation gradients of the supermartensitic steel. The texture is characterized by the rotated cube, goss and rotated goss components and a <111>//ND gamma fiber. EBSD also showed that the martensite phase has a nearly Kurdjumov-Sachs crystallographic orientation relationship with the parent austenite phase.
Keywords
Supermartensitic steel, dilatometry, microstructure, texture, crystallographic relationship.