Brazing SS to 4130 !?!? Can This Be Done?

[tc7]

I quess it can - we have an old Navy drawing (vintage 1968)for a vent line on a high pressure vessel which requires brazing a 304 stainless tube (.25" O.D.) to 4130 socket type fittings. There is no specification for filler, flux or otherwise.

Any advice on this?
Thankyou.

Other Info: Even though it is a vent line, the bleed valve is remote from the tank so the line and fittings always see pressure).

 

[metengr]

tc7;
Yes, it can be done. Go to the site below for information on flux and recommended filler metal;

http://www.handyharmancanada.com/thebrazingbook/contents.htm#Index

This is one of the better background sources on brazing and filler metal selection. I would not use any Cd-containing filler metals due to toxicity during brazing.

After brazing, I would recommend a liquid PT if this joint contains pressure.

 

[tc7]

Thanks Met-
That is a great site and I found my way to their partner company, Lucas-Milhaupt. Excellent folks - they made me aware that this odd joint combination is prone to interface corrosion and recommended a nickel containing brazing alloy. I'm all set.
Regards,
t