8. Welding ProcessesThere are different welding processes used to join different parts of the automobile exhaust system. These include: 8.1. High frequency resistance welding8.2. High frequency resistance welding8.3. Laser welding8.4. Durable spot welding8.5. Gas tungsten arc welding8.6. Brazing and8.7. Gas metal arc welding (GMAW) with solid or metal core wires. These welding processes can be made semi-automatic, mechanized or fully robotic depending on various factors. Among all these welding processes, GMAW process is mainly used to manufacture the exhaust system. Additionally, the GMAW process using stainless steel metal core wires is much easier and less expensive than solid wires to weld new stainless steel materials used in the manufacturing of automobile exhaust system. [ ]8.1. Resistance weldingA welding process in which joining occurs by heat produced by the resistance of the workpiece to the flow of low-voltage, high-density electric current in a circuit. The workpiece is the circuit part. In resistance welding, pressure is constantly applied to maintain a continuous electrical circuit. This pressure will help the heated pieces form together. In this process, the parts are not melted to be assembled, but they are heated to a plastic state just before melting, then forced together to be assembled. In automotive exhaust welding, bead welds are typically used to weld one part to another. So, the type of resistance welding process used in automobile exhaust to produce weld welds is high-frequency resistance welding.8.2. High Frequency Resistance Welding In this process, the welding current is supplied at high frequency (200-500 kHz). This high frequency allows localized heating. So this...... middle of paper ...... systems are-12.2.1. Arcaloy MC 308L12.2.2. Arcaloy MC 309L12.2.3. Arcaloy MC 316L.A9.2.1. Arcaloy MC308L (AWS A5.9-93, EC 308L): AISI types 301, 302, 304, 304L, 308 and 308L are welded by Arcaloy 308L.9.2.2. Arcaloy MC309L (AWS A5.9-93, EC 316L): It is used to weld different joints made between carbon steels and various stainless steels.9.2.3. Arcaloy MC316L.A (AWS A5.9-93, EC 316L): This type of austenitic grade is used to weld AISI 316 and 316L stainless steel grades to prevent pitting corrosion. The following table shows the composition of the austenitic grades of SSMC wires - Table 9: Composition of the austenitic qualities of SSMC wires [24] Ferritic and austenitic SSMC wires from the Arcaloy family are generally packaged in spools of 15 Kg, 20 Kg and even in 227 Kg marathon packs but these 227 Kg marathon packs are generally preferred by exhaust system manufacturers.