X-Ray Diffraction Analysis of Residual Stresses in the Premium Rails Welded by Flash Butt Process

Análise de Tensões Residuais, Via Difração de Raio-X, em Trilhos Premium Soldados Através do Processo de Centelhamento

Abstract:

This work is distinguished by searching for a non-destructive technology, and X-ray diffraction was validated by the XStress 3000 analyser. Measurements of residual stresses in the welded zone of premium pearlitic rails was performed, rail surface hardness of 370 HB and 0.79% carbon content. The welding of the rails was done by flash butt process, performed by Schlatter GAAS 80 stationary equipment. The results of the tensile and compressive stress measurements identified the residual stresses in the welded zone, with specific zones of tensile stresses misplaced at the weld center, with values up to 391 MPa, and compressive stresses, with values up to -166 MPa, as it moves away rails weld center. An important point of this study is the residual stress measurement considering a complete welding process, including: pre-grinding, flash butt welding, heat treatment, finishing grinding and straightening. Lastly, was observed the welding technique potentially can induce residual stresses at rails.

Key-words:
X-ray diffraction; Residual stress; Flash butt welding; Pearlitic premium rails; Non-destructive tests