incoloy 800HT - welding heat treatment

Date 02-28-2015 12:04

We find HAZ welding cracks during stopage inspection with PT in 760ºC transferline of 15 years old INCOLOY 800HT 6" SCH 160 piping - Code ASME B 31.3. As the defects was removed by grinding, the equipment return to operation, and we are preparing its substitution in the next stopage.
As our conclusion to the cracks occurency: stress relaxation cracking.

My question: its necessary after the weld of new piping, the use o Heat Treatment? If yes, we can use the ASME Sec VIII Div 1 - item UNF 56 (e)Post heat treatment of UNS Nº N08800, N08810, and N08811 Alloys procedure?

tks

By 803056

Date 02-28-2015 16:16

This site might provide some insight and push you in the right direction.

www.specialmetals.com/documents/Incoloy%20alloys%20800H%20800HT.pdf

Best regards - Al

By greggianin (*)

Date 03-05-2015 13:16

tks Al, but that site don't clarify me the necessity. Do you know another way?

By 803056

Date 03-05-2015 14:23 Edited 03-05-2015 14:25

That particular company, Special Metals, has a technical staff that can provide you with the information you need. They specialize in stainless steels and high nickel alloys. They are the experts.

Another source for high nickel alloys is Carpenter Technologies, located in Reading, PA. Likewise, they have a technical department that can provide information on the best methods of fabricating, welding, stress relieving, etc.

All it takes is a phone call or an e-mail to speak with the people with the most technical knowhow in the industry.

ASME B31.3 is for piping, ASME Section VIII is for unfired pressure vessels. The Owner is responsible for determining which ASME code is appropriate and applicable. Generally, you don't use the requirements for unfired pressure vessels for piping.

Best regards - Al

By greggianin (*)

Date 03-07-2015 10:52

TKS AGAIN. I WILL CHECK THE CARPENTER SITE.