Weld quenched with rain water

Materials Science, Metallurgy, Welding, NDTs, Reliability Assessment, Failure Analysis, etc.
arcpro
Posts: 299
Joined: 16 Apr 2010, 18:46
Area of interest: Manufacturing Engineering

Re: Weld quenched with rain water

Post by arcpro »

saadsh,
P22 is highly hardenable steel and even controlling prehating temperature, the best hardness reading comes to be around 290 HB. There are certain ways you can control the hardness of P22 steel during welding like using high preheat temperature 250 deg C, use of temper bead technique, post heating to 300-350 deg C and then to cool under insulation. And if all these conditions are met, even then you are not sure about the reading of hardness whether it will come in acceptable limit or not. And in case, if rain water has been splashed over the weld how hardness would be in acceptable range; as per my knowledge, it would never be.
sakib321
Posts: 64
Joined: 02 Aug 2010, 04:06
Area of interest: Metallurgy Engineering

Re: Weld quenched with rain water

Post by sakib321 »

@all
ALL OF you are talking about the hardness acceptable limit of P22 material
is there any document or para that refer the acceptable limit for hardness of different materials
i have seen ASME SECTION II part A but i got nothing about Hardness limit
will you quote any code with reference clause for acceptable limits of hardness of different materials?
Sakib Jalal
ashfaqanwer
Site Moderator
Posts: 434
Joined: 16 Mar 2010, 03:36

Re: Weld quenched with rain water

Post by ashfaqanwer »

We are talking about the hardness limit of P-22 piping weld after PWHT and the hardness acceptable values have been given in ASME B31.3 for all piping materials in heat treatment table 331.1.1and for P-22 (P.No. 5), the max. acceptable value is 241 HB.
Ashfaq Anwer
-thepetrostreet.com
sakib321
Posts: 64
Joined: 02 Aug 2010, 04:06
Area of interest: Metallurgy Engineering

Re: Weld quenched with rain water

Post by sakib321 »

oka thanks for this info

is there any such reference of Hardness after PWHT of pressure vessel's weldment fabricated as per ASME VIII?
Sakib Jalal
ashfaqanwer
Site Moderator
Posts: 434
Joined: 16 Mar 2010, 03:36

Re: Weld quenched with rain water

Post by ashfaqanwer »

ASME BPVC Sec. VIII does not require hardness after PWHT operation.
Ashfaq Anwer
-thepetrostreet.com
sakib321
Posts: 64
Joined: 02 Aug 2010, 04:06
Area of interest: Metallurgy Engineering

Re: Weld quenched with rain water

Post by sakib321 »

then how u ensure that PWHT of vessel fabricated as per ASME BPV SEc VIII is conducted properly?
Sakib Jalal
ashfaqanwer
Site Moderator
Posts: 434
Joined: 16 Mar 2010, 03:36

Re: Weld quenched with rain water

Post by ashfaqanwer »

I suggest that if you want to discuss further, initiate a new thread with a defined subject.
Hope you understand.
Ashfaq Anwer
-thepetrostreet.com
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