Analysis of spot welding on gas & liquid distribution pipes using microstructural methods.

The oil and gas industry currently requires piping to be used as a fluid transfer from one place to another. Most of the oil and gas piping uses metal as its raw material. One of the pipe materials used in the oil and gas industry is SA 312 Tp 304L. In this research will be conducted which compares the mechanical properties of SA 312 Tp 304L with GTAW welding variations, and combinations (SMAW+GTAW). Testing is done using macro structure testing methods and testing mechanical properties such as Tensile testing, and Vickers testing. Macro test results with 10 times magnification using macro Etching in the form of 10% oxalic acid obtained no visible porosity, or cracks in the weld metal, on testing the maximum tensile strength in combination welding (SMAW+GTAW) of 591.69 N / mm², and 557.27 N / mm² in GTAW Welding, of the two methods, still meet the material standard requirements, and the results of Vickers test: the greatest strength is in the weld metal, namely SA 312 TP304L material, the average value of GTAW Welding is 244 HVN and Welding Combination (SMAW+GTAW) of 210 HVN. From the value of the violence, the two methods get very different results. One of the causes of the difference in the value of this hardness is due to a slight difference in welding speed and welding metal cooling rate [ABSTRACT FROM AUTHOR]