Welding is the most widely used technique which is preferred by manufacturers to join metals and alloys efficiently and to add value to their products.The most critical issue however, is to have a perfect weld and to do so with cost efficiency. This is easier said than done but a professional approach with expert advice can resolve the technical issues.
Faced with the problem of improving the spot welding electrode life and minimizing the indentation mark in welded components, an appliance processor went about it professionally with technical help.
Expression of the problem:
- The needed electrode dressing frequency was once in every 15 components.
- This lead to lower electrode life and productivity loss.
- Aesthetics required the customer to use flat bottomed large diameter electrodes (diameter 25 mm), which lead to shear type failure (TSS) of the nugget due to improper fusion of a/c of lower current density.
Details of trial:
- Top electrode remained unchanged given the aesthetic requirement of the outer surface.
- Bottom electrode changed to 8mm round bottomed conical electrode to improve the current density.
- Current density increased from 6 to 8 KAmps/mm2 to 13 Kamps/mm2.
- No dressing was required for 60 spots as against electrode dressing of once in every 15 spots thanks to a superior weld nugget was superior.
- Indentation mark, caused on the weld area due to spot welding electrode pressure, eliminated after the modification.
- Mass trial and customer feedback to confirm improvement of practice.