welding C.S to 304 Stainless steel

Date 10-12-2010 10:30

hello dear friends
I need to your helps, I want welding A514 carbon steel to 304 stainless steel with 625 or 82 inconel filler metal with GTAW. I want to understand that, Inconel filler is better than 309 filler metal? particularly for tensile strength in elevated temperature.
and for more information, what is the maximum service temperature of carbon steels like A514? and is there positive effect on corrosion resistance of weld with Inconel filler rather than 309 filler?
thanks alot

By js55

Date 10-12-2010 10:36

In general if you are welding to carbon steel its who cares corrosion wise as to whether you use 309 or nickels, except for the cost. However, if you are intending an elevated service temp nickel is the general choice since its coefficient of thermal expansion is quite close to carbon steels and minimizes stress at the fusion zone. Whereas SS realizes quite an expansion and can stress the fusion zone between it and the CS.

By iesca

Date 10-12-2010 21:11

Is it an ASTM A514 Steel? If yes, ASTM A514 is an low alloy steel, quenched and tempered. To weld High Strength Low Alloy Steels the weldment shall be preheated to prevent cracking, but the preheat temperature shall be carefully controlled in order to prevent chrome carbide precipitation in austenitic stainless steel.

Hector Garcia

By kcd616

Date 10-12-2010 21:58

It can and will crack, but there are certain filler metals to use to prevent that.
But the carbon steel will still have some problems.
I know this because it sounds like what is used on a nuclear power plant.
So Hobart, contact the US Nuclear Regulatory Agency.
Just give them all your information of WHO and WHERE you are.
They will love to have all the information you give them and respond in kind.
Hope this helps.
Thank you for your time and consideration.
Sincerely,
Kent

By hobart

Date 10-13-2010 08:53

thank ou dear friends
I want undestand that, carbon and low alloy steels, particularly a514, a516, a204 and a302, have a sufficient resistance to stress corrosion cracking condition? and what about effect of filler metal on this condition.
thanks

By Eutectic (**)

Date 10-13-2010 09:34

Dear Hobart,

It is a bit difficult to answer this question based on the information given, you need to consider three things
1. Is your material susceptible to SCC ( CS very likely)?
2. Does the service promote SCC ( H2S/ sour, Chlorides, Caustic etc)?
3. Is there stress involved?

Look at all these factors together in application to determine / evaluate your chances of SCC.

By madibaa (*)

Date 10-13-2010 11:47

dear eutectic
if my material is a302 and my service is caustic, scc occur?

By js55

Date 10-13-2010 10:24

First of all, the filler metal choice will not effect any properties of the base metal. Second, if the SCC you are speaking of is CSCC then perhaps you should consider the nickel alloy as opposed to 309.