I have an application that requires butt-welding 2 pieces of .030 cold rolled steel together. The components are also edge molded with rubber and the rubber must stay under 180 degrees or suffer bond failure. The rubber will be about 1/8 inch away from the seam on both components. The smaller component (ear) is about 1 ¾ square and will only butt up with the larger component on one edge and in a straight line. The part is a 12” x 8” metal carrier with edge molded rubber for a Diesel Engine Rocker Cover Gasket application. Because of this being a gasket, the weld cannot stand proud of the metal carrier surface. It must be flush or below. Coining down the material prior to welding in the seam area could be done if so needed. Do I have any options other than Laser Welding as this is too costly. 2 ears per gasket, 160,000 gaskets a year.
You can try PAW. With some of the power sources out now you can weld some very thin materials. These machines are capable of welding from 0.5 amp and up and you can dial in 0.5-amp or 1-amp intervals.
I don’t think that you will be able to keep the temperature below 180 degrees F but I could be wrong. One way to find out is to run calculations to determine the size (width) of the HAZ. You can also determine peak temperatures at various distances from the fusion boundary i.e., 1/32, 1/16, 1/8. To do this you will need your welding parameters. Amperage, voltage, Travel Speed, liquids of metal (should be about 2750 F) initial base metal temp, and arc efficiency.). Running the calculations will give a good feel for the size of the HAZ and the temperatures from the fusion boundary. The calculations can be found in the Welding Handbook Volume 1 starting on page 76-84 you can also find them in ASM Handbook Vol. 6 Page 8-18.
Good luck
By -
Date 04-22-2001 18:47
Are you sure about laser welding being too expensive? I know that the equipment is expensive, but you are describing an ideal laser welding application, from an economic point of view. (High volumes) While the equipment for other processes may be cheaper, I suspect that when you calculate in welding time and reject rates, laser welding may not be so expensive after all.
Regards
Niekie
Does the process allow for the use of heat sink material such as small copper (Maybe even water cooled) adjacent to the HAZ. Its just a thought.
Gerald Austin
Iuka Mississippi
http://www.geocities.com/pipewelder_1999/
