Influences of MMR, PWHT and notch location on fatigue life of HSLA steel welds

Abstract Welding of High Strength Low Alloy Steels (HSLA) involves usage of lower, more even and higher strength filler materials (electrodes) than the parent material depending on the application of the welded structures and the availability of the filler material. In this investigation an attempt has been made to study the influences of mis-match ratio (MMR), Post Weld Heat Treatment (PWHT) and notch location on fatigue life of HSLA steel welds. A Shielded Metal Arc Welding (SMAW) process has been used to fabricate the butt joints. A Centre Cracked Tension (CCT) specimen has been used to evaluate the fatigue life of welded joints. Fatigue experiments have been conducted using a servo hydraulic controlled fatigue testing machine at constant amplitude loading ( R =0). The Design of Experiments (full factorial design) concept has been used to optimise the number of experimental conditions. Analysis of Variance (ANOVA) method has been used to identify the significance of main and interaction effects. A mathematical model has been developed to predict the fatigue life of HSLA steel welds using Regression analysis.

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