pre-heating of steel before welding

By zimbo Date 06-02-2002 14:02

I,m trying to find out how to calculate the pre-heated temperature required when welding GMS plates to a base plate over a certain thickness - in this case 38mm thick gusset plates to a 50mm thick embed plate. Also, what is the procedure for producing the correct temperature once calculated.

If anyone can offer some advice it would be much appreciated

Cheers

By Niekie3 (***)

Date 06-02-2002 19:40

I assume GMS means general mild steel? If not, please let me know.

The first thing would be to check the fabrication code or client specifications. Often these have prescribed values to use. In the absence of these, there are standards around that address these issues. The one we generally use is a BS standard. As I am at home, I do not have access to the number. If nobody else gives it, I will let you have it later.

In these standards, there are graphs that correlate the carbon equivalent, combined thickness and heat input to the pre-heat temperatures. It would be very difficult to actually give all the details here.

Hope this helps

Regards
Niekie Jooste

By Michael Sherman (***)

Date 06-03-2002 11:43

AWS D1.1:2000, 3.5, 3.5.1, 3.5.2, 3.5.3, 5.6, 5.18.2, Annex XI, Commentary Annex XI, Tables 3.2 (This table is the most helpful). Temp sticks or a themocouple thermometer will help you keep the proper temperature. Once the proper interpass and preheat temperature has been determined, put a Temp stick crayon mark next to the area to be heated and heat it up until it melts. Over 38 mm thru 65 mm is 110 C. preheat and interpass.This is right off of page 46 in AWS D1.1:2000.

Respectfully,
Mike Sherman
Shermans Welding