HARDNESS AND TENSILE STRESS STEEL WELD ST-37 ON VERTICAL AND HORIZONTAL POSITION
By : AFRIAN SUGIHARTO
Faculties : Fakultas Teknik
Department : S1 Teknik Mesin
Las is a way of connecting the metal by heating to melt. There are many techniques in welding one of which is the SMAW welding techniques. This welding technique is generally widely used for connecting the construction of the bridge, connecting pipes and all materials made of metal. Testing is done by making as many as 5 specimens for welding positions vertical and 5 horizontal specimens for welding positions. The method used for testing, namely radiography, ultrasonic NDT, metallographic test, Vickers hardness test and tensile test. The test result show value of a strains greater in vertical welding positions are greater 0118 kg / mm2 of horizontal welding positions, and has a modulus value that is smaller than the horizontal welding position. Whereas horizontal welding position has a strains value smaller than the vertical welding position but has a modulus greater value of is 178.92 kg / mm2 compared to the vertical welding position. On the Vickers hardness test hardness value in the horizontal position is greater than value of the vertical welding position. On testing radiographic taken 1 biggest flaw of vertical and horizontal welding positions. Then biggest flaw in the test with ultrasonic NDT and the result is no defect happens. On the metallography test performed on the fault area and the result is a kind of ductile fracture in the second position.
Keyword : weld, vertical, horizontal, NDT, defect.