P number

[3lilaggies]

Does ASTM A355 Gr. A have a P number? It's not listed in ASME section IX.

 

[metengr]

There is no assigned number for this material. Even AWS B2.1-2005 has no assigned M-No.

 

[3lilaggies]

So how do I find the pre heat and PWHT?

 

[metengr]

My suggestion;
1. Calculate the carbon equivalent (CE)
2. Follow this FAQ faq330-1077 for preheat selection
3. For PWHT, you need to determine the original heat treatment condition of this material. If it was tempered, the PWHT temperature should remain 50 deg F below the original fabrication heat treatment tempering temperature.

 

[3lilaggies]

thanks

 

[unclesyd]

I have a listing that has A355(A) equivalent to A519
(AISI 7140).
AISI 7140 in addition to the 0.40 C; has 1.6 Cr; 1.15 Al

With the Al welding could get a little tricky.

I don't have any welding parameters on either materials only heat treating specifications for AISI 7140.

 

[3lilaggies]

thanks

 

[metengr]

3lilaggies;
What exactly are you trying to do with welding this material? Unclesyd peaked my interest and I looked up this ASTM Specification. The Grade A is an alloy steel for nitriding. The bars shall be supplied in quenched and tempered condition (min of 1112 deg F) to produce a spheroidized structure.

 

[3lilaggies]

We are doing an overlay of stellite. When the welders preheat it it becomes very hard to weld. I was hoping that someone might know a trick as to how to do it successfully. The Bars that we do the overlay on tend to warp alot, so we are looking for a different solution.

 

[metengr]

Ok. I presume you are using Stellite 6 for hardfacing. If this is the case, you need to limit the preheat and interpass temperature to 600 deg F. Second, bead placement is critical for welding Stellite 6. I would suggest using tight stringer beads, no weaving. Distortion is what it is because of welding.

As a side note, why are you even using this grade of alloy steel as a substrate material for Stellite 6? The current alloy grade was developed for nitriding capabilities not necessarily for hardfacing with Stellite.

 

[3lilaggies]

its a difficult answer to give. Only that the customer requested this grade and type. They wouldn't have it any other way.

 

[unclesyd]

What is the thickness requirements of your Stellite overlay?

If if your thickness will permit you may have to put a bond coat on the shaft. I would get in touch with Deloro Stellite and See if Nickel Aluminide might work in your case.

Another possibility is using a laser applied coating for the Stellite 6.

Another possibility is the use of a Stellite sleeve if thickness permits.

 

[3lilaggies]

location will not permit sleeve, but we are looking at the possibility of applying with a laser. Thank you for your comments.