Evaluation of Crystallographic Texture in SS316L Steel by Ultrasonic Signal Analysis

Abstract

An attempt has been made to evaluate crystallographic texture in AISI 316L austenitic stainless steel through the analysis of ultrasonic signals. Results of ultrasonic signal analysis and birefringence effect were compared with orientation distribution function (ODF) of the material (macrotexture) evaluated using conventional X-Ray diffraction. In polycrystalline aggregates, ultrasonic wave velocities were strongly affected by crystallographic texture. In this work, 70% rolled steels of AISI 316L stainless steel was annealed isothermally at temperatures 450oC to 750oC at an interval of 50oC with holding time of 30 minutes at each temperature. Ultrasonic longitudinal and transverse velocities were measured in each annealed sample. Power spectrum of the windowed ultrasonic signal as well as peak shift of the shear wave signal were analyzed and co-related with the texture data. It was seen that power spectrum analysis of windowed signal could be a potential tool for evaluation of crystallographic texture in polycrystalline materials.