Effect of PWHT Cycle on Microstructure and Mechanical Properties of 1.25Cr-0.5Mo Weld

Amit R. Patel

doi:10.37591/joeam.v10i1.1636

Abstract

Post Weld Heat Treatment (PWHT) is a process of reducing residual stresses and enhancing material properties of any material after welding. The process depends on many parameters like type of material, the thickness of material, PWHT temperature, soaking time, heating and cooling rate, etc. The Post Weld Heat Treatment process of material could effect on tensile strength, impact toughness, hardness, microstructure, etc. If the Process of PWHT is performed incorrectly or neglected altogether, Residual stresses in material combine with external loads which may exceed material’s design limit. In present work, the effect of a different PWHT cycle is analyzed for ASTM A691 Gr. 1.25Cr alloy steel which is used for high temperature and high-pressure service in oil and gas industry. The regions corresponding to the weld metal and heat affected zone were studied. The specimens were tested for welding quality, microstructure, and mechanical properties after Post weld heat treatment at the different temperature and soaking time.

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