Does LTCS Weld Joint with above 20mm thickness need PWHT?
Does LTCS Weld Joint with above 20mm thickness need PWHT?
(OP)
As per ASME B31.3 Table 311.1.1 PWHT shall be performed for the Weld Joint with Base Metal P Number (P) 1, Weld Metal Analysis Number (A) 1, and above 20mm thickness. LTCS Pipe A333 Gr.6 Welded with Consumables ER80SNi-1 and E8018-C3 has P Number (P) 1 and Weld Metal Analysis Number (A) 10.
Please Confirm Whether PWHT is to be performed for LTCS weld joint above 20mm thickness with base metal P Number (P) 1 and Weld Metal Analysis Number (A) 10?
Please Confirm Whether PWHT is to be performed for LTCS weld joint above 20mm thickness with base metal P Number (P) 1 and Weld Metal Analysis Number (A) 10?





RE: Does LTCS Weld Joint with above 20mm thickness need PWHT?
Looking the welding consumables used it looks to me , the design requirements involve NACE,MR-0175, which calls for a maximum weld and HAZ hardness of 22HRC. If the above hardness levels can't be met in as welded condition, then PWHT is a must.
A combination of ER80SNi-1 and E8018-C3 welding consumables,would not give weld hardness of less than 22HRC in as welded conditon.
Hence looking at all the pros and cons, welds should be subjected to PWHT.
Thanks.
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario, Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299
RE: Does LTCS Weld Joint with above 20mm thickness need PWHT?
As per B-31.3, Table 331.1.1 PWHT would be required if the thickness of C-Mn steel weld exceeds 20 mm or 3/4".
this is only if 'A' number is 1. in this case 'A' number is 10. So what about the influence 'A' number in Table 331.1.1 of B31.3?
RE: Does LTCS Weld Joint with above 20mm thickness need PWHT?
RE: Does LTCS Weld Joint with above 20mm thickness need PWHT?
you replied 'A' number is inconsequential. if it is inconsequential, then why B-31.3 table included 'A' number. how can I make sure 'A' number is inconsequential?
RE: Does LTCS Weld Joint with above 20mm thickness need PWHT?
Governing Thickness(Clause 331.1.3) for PWHT in B31.3 code is the nominal thickness at the weld joint (Base Metal). Additionally, the intent of adding "A No" in Table 331.1.1, is to ensure the minimum chemical analysis of the weld metal to be used matches the base metal chemistry, i.e A No 1 matches P No 1
In many instances LTCS base metals are welded with Nickel containing fillers/electrodes. However the PWHT (Holding Time & Temp) criteria is based on the BM.
If you look though Table 331.1.1, the PWHT Temp range is almost same for both P1 base metal and A10 weld consumable, with minor variations in holding time.
Holding time could be important if the design specification calls for a hardness restriction or specific impact requirments.
Thanks
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario, Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299
RE: Does LTCS Weld Joint with above 20mm thickness need PWHT?
Birken
RE: Does LTCS Weld Joint with above 20mm thickness need PWHT?