PENGARUH WAKTU TAHAN PADA PROSES SPOT WELDING MATERIAL BEDA JENIS SUS 304 DAN DIN 1.4003 TERHADAP KEKUATAN TARIK DAN STRUKTUR MIKRO

Stainless steel is a material that is strong and resistant to corrosion. This material is widely used in the manufacturing industry, especially in land transportation. In the process of making the body, two types of stainless steel are used, namely SUS 304 and DIN 1.4003. Joining these two metals is difficult by fusion welding, because it will cause problems that can be detrimental to the construction. Some literature suggests using a welding method that has no excess heat and is controlled.

In this study using 1 mm thick SUS 304 material and 2 mm thick DIN 1.4003. Then, electrical resistance welding was carried out with a current of 9 kA and a variation of the welding time used, namely 0.16 seconds; 0.20 seconds; 0.24 seconds; 0.28 seconds; and 0.32 seconds. The tests carried out in this study were the Tensile Shear Test, the Macro Sectional Test, and the Micro Structure Test which occurred in the two materials being joined.

The results showed that the longer the welding time used, the greater the value of the tensile stress and the diameter of the weld nugget. The highest tensile stress value in this study was 246,82 N/mm2 with a welding time of 0.32 seconds. While the largest nugget diameter was also obtained from a welding time of 0.32 seconds with a diameter of 7.2 mm. Then the results of the micro structure testing carried out showed no difference at each variation in welding time, because the heat input at each time variation was the same. The phases formed are the austenite phase and the ferrite phase.

Keywords : stainless steel, electric welding resistance, nugget, welding time, tensile shear test, macro sectional test, micro structure test