The Effect of Heating Temperature in Static Thermal Tensioning (STT) Welding on Mechanical Properties and Fatigue Crack Propagation Rate of FCAW in Steel A 36

The trend in mechanical design and manufacturing process is marked by the use of thin structures to reduce product weight and fuel savings. It is known that the main problem related to the welding of thin plates is distortion and residual stress which influence fatigue performance of welded structures. The aim of this study is to minimize distortion, improve the mechanical properties and to increase fatigue crack growth resistance of flux-cored arc A 36 steel welded joints using static thermal tensioning (STT) process. In this research, FCAW welding was conducted with and without STT process. The voltage, current, and heat input were 40 Volt, 210 Ampere and 2.184 kJ/mm, respectively. The position of both heaters was 80 mm, and weld with the cooling system was heated near weld center line. During the experiment, the weld metal cycles were measured using data acquisition. After completing the welding process, a sequence of the experiment was conducted including chemical analysis, measurement of distortion, tensile strength and hardness measurement and fatigue tests. Results of this research show that the STT-treat weld joints process performed at temperature of 200 degrees C produces the highest quality of weld, marked by lowest distortion, high tensile strength, low hardness in weld metal and improvement of fatigue performance