Abstract:
The welding process is an effective repair process for adding a metal layer on a worn surface of an agricultural machinery part that was damaged from use. Therefore, it is important to find the optimal welding process parameters that can improve the mechanical properties of a worn surface in order to continuously prolong the service time of the machinery parts. This work aimed to study the effect of an aluminum cladding parameter on a S45C carbon steel surface properties by using gas tungsten arc welding.
The material used in this experiment was a hollowed cylindrical shape of JIS - S45C medium carbon steel which had an outer diameter of 135 mm, an inner diameter of 85 mm, and a length of 100 mm. An aluminum weld metal was produced on the outer surface of the cylinder by using gas tungsten arc welded with an aluminum wired electrode. The welding process parameters were welding currents of 170 - 200 A, a welding speed of 100 mm/min, wire feed rates of 200 - 800 mm/min, and the single, double and triple welding layers of aluminum. The welded specimens were mechanically prepared and investigated for hardness, wear resistance, and macro/ micro structure.
The summarized experiment results are as follows. The welding parameter was optimized with a maximum hardness of 846.3 HV and a weight loss of 1.04 percent when testing the double welding layers at the welding current of 190 A, the welding speed of 100 mm/min, and the wire feed rate of 200 mm/min. Increasing the welding current and the number of overlapping layers tended to increase the hardness of the aluminum cladding on the carbon steel surface. A chemical composition analysis of the joint interface showed that the formation of Fe-Al intermetallic compound which tended to increase hardness and wear resistance of the joint interface.