I am working on a project that requires me to weld with medium strength steel. I normally weld with low carbon and high strength steel but the medium strength steel is new to me. Usually I work with the "Dolfi" or "Hayes" welding chart that was provided to me by Ford. The company that this project is different from Ford and I can't find any other info on this type of medium metal. It would help to know if this metal is more or less like low carbon or high strength steel. Thanks for the help. Steve

-- steve kosenko (sck@weldmation.com), April 25, 2001

Answers

sTEVE,I need to know the carbon count of the steel. We can weld up to50 points of carbon and heat treat back to parent metal ductility right in the machine by doing quench and temper. If you want help in the Detroit area, contact Mike Kroman at Detroit center Tool. Mike is one with lots of experience. 810 323 8438 or www.dct-inc.com Tell him Tom sent you.

-- tom mitchell (INFO@ATEKCORP.COM), April 25, 2001.

I’m assuming you are referring to steel having a carbon content of .25% to .45%. It is not clear if you are arc welding or resistance welding. A quick carbon equivalent, weldability check would be in order to determine if any special weld procedure might be anticipated.

CE=C + (Mn/6) + (Cr/5) + (Mo/4) Carbon Equivalent = Carbon % + (manganese % )/ 6 +(chromium % )/ 5 + (Molybdenum %)/4 Example: Carbon .25%; Manganese .75%; Chromium.05%; Molybdenum.04% CE= .25+(.75/6)+(.05/5)+(.04/4) CE =.395 No anticipated problems requiring special weld schedules.

This formula figures in carbon, manganese, chromium, and molybdenum, all of which cause hardness in the weld. If carbon equivalent (CE) is less then .50, it most often can be welded without preheat or post heat treatment.

Resistance welding schedule for medium carbon steels rule of thumb would be; 10% less current than low carbon steel 10% greater electrode force than low carbon steel Longer weld times to retard quench rate. Possible post heat treat schedules required.

Bob Balla T. J. Snow Company, Inc. 6207 Provence Street Chattanooga, TN 37421

Phone: 423-894-6234 423-308-3161 (direct line) Fax: 423-892-3889 e-mail: bobballa@tjsnow.com

-- Bob Balla (bobballa@tjsnow.com), April 30, 2001.