EFFECT OF PREHEATING TEMPERATURES ON IMPACT PROPERTIES OF CHROMOLY ALLOY STEEL 4130 WELD USING GAS METAL ARC WELDING

The influence of the preheating temperature on impact properties was studied in this work. The base plate made of chromoly alloy steel 4130 was welded by using gas metal arc welding process. The electrode used is ER70s-D2. Single ‘V' butt joint configuration is used in this study. The base metal chromoly was preheated at different temperatures such as 150°C, 200°C and 250°C. The effect of preheating temperatures on the impact properties is studied. Impact test was conducted in different working temperatures. Pendulum type impact machine was used to evaluate the toughness. From this investigation it was found out that the toughness varies based on preheating temperature. The microstructure of the welded metal for different temperature of preheating has been analyzed. The microstructure reveals that ferrite and pearlite boundaries influence the impact properties. It is evident that the preheating temperature has strong correlation with the toughness of weldments.