Welding 4140 to T-1 high tensile steel
Welding 4140 to T-1 high tensile steel
(OP)
We have received intstructions to weld 6.5" diameter to a couple of T-1 1" and 1.5" plates.
The problem we are having is no weld procedures to weld heat treated 4140 to T-1.
The joint is very heavily stressed and has to made of these steels.
I am trying to work out the preheat for and what I have found is I need a lot higher preheat for 4140 than what the maximum interpass temperature is for the T-1 plates.
Is it possible to weld these steels together with the conflicting preheat and interpass temperatures?
What happens to the properties of T-1 plates if I pick the higher preheat temperature?
What should these preheats be?
We can't reheat treat this joint after welding.
Appreciate your help.
The problem we are having is no weld procedures to weld heat treated 4140 to T-1.
The joint is very heavily stressed and has to made of these steels.
I am trying to work out the preheat for and what I have found is I need a lot higher preheat for 4140 than what the maximum interpass temperature is for the T-1 plates.
Is it possible to weld these steels together with the conflicting preheat and interpass temperatures?
What happens to the properties of T-1 plates if I pick the higher preheat temperature?
What should these preheats be?
We can't reheat treat this joint after welding.
Appreciate your help.
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RE: Welding 4140 to T-1 high tensile steel
What is the heat treatment condition of the 4140? The T1 steel is a high strength low alloy and you need to watch heat input to avoid altering bulk mechanical properties.
The preheat for 4140 can be as low as 250 deg F, which fits well within the preheat range for T1 steel. The interpass temperature should be less than 400 deg F, period.
Can you come back with your filler metal selection and type of weld joint detail?
RE: Welding 4140 to T-1 high tensile steel
RE: Welding 4140 to T-1 high tensile steel
First I will let you know I am in Australia and some of the units, materials are metric and available Australian steels.
T1 is equivalent to Bisalloy 80 and 4140 is also called 4140 in Australia.
the 25mm (1") Bisalloy 80 (T1) is running along the center axis of the 67" long 4140 (170mm diameter or 6.69" diameter).
There are 6 plates welded perpendicular to the 4140 axis made of 40mm (1.5") Bisalloy 80 (T1) plate with a hole for the round bar to go through at about 10" centres.
The 4140 is solid round bar. Here is the link I just found for the material http://ww
I planned GMAW or should we use something else?
Thanks.
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RE: Welding 4140 to T-1 high tensile steel
Thanks for the specifics. The Bisalloy 80 in the 25mm thickness has a carbon equivalent of 0.50, which is indicates good weldability with moderate preheat.
The GMAW process is fine for this application, and the filler metal strength you posted looks acceptable.
From your description above, it would appear you are using fillet welds to join the Bisalloy 80 (T1) to the 4140. If this is the case, use the preheat recommendation and interpass temperature I provided above and use continuous fillet welds (wrap the welds around the entire plate) for the Bisalloy 80 plates.
I would suggest you wrap the T1 plates after welding to slow cool (if necessary), and I would have nondestructive testing (NDT) performed, like magnetic particle or liquid penetrant to ensure defect free welds.
RE: Welding 4140 to T-1 high tensile steel
You suggest to wrap the T-1 plates.
Do you have a link to a good material to use for a wrapping material?
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RE: Welding 4140 to T-1 high tensile steel
You can get these material at any industrial insulation supply house or any industrial contractor. Mention Cerawool or Kaowool. The blankets come in 25 ft rolls and cloth in larger rolls 100 ft +.
metengr and myself would reach for the A cloth
RE: Welding 4140 to T-1 high tensile steel
Ed Danzer
www.danzcoinc.com
www.dehyds.com