Aluminum welding in annealed form

Date 06-22-2015 15:06

Hi all, I have another basic question regarding aluminum welding.

I deal with welding of aluminum 2219 alloy. Welding is carried out in annealed form followed by solution treatment,quenching and artificial aging to get T6 Temper.

If we weld in T6 then we will qualify procedure according to the code then we will get it complete heat treated to get back T6 temper again. As far as i know, resulting weld in both cases will have same properties if done in identical conditions( Correct m i am wrong).

My question is why all the literature talks about welding in T6 condition.If ultimately we are to heat treat it again then what extra benefit are we achieving by welding in T6 condition. To me, welding in T6 is waste of time and money. First we purchase costly T6 then we qualify procedure,then we reheat treat it again to get back the uniform T6 .

Why not code recommends welding of aluminum in an annealed form?

Thanx for reading the post and correct me where ever i am wrong.

By 803056

Date 06-23-2015 00:08

Many applications do not require PWHT.

The welded joints are simply located in areas of low stress.

Don't forget, your PQR must be qualified with the PWHT you will be using in production.

Al

By waqasmalik (**)

Date 06-23-2015 07:28

It means i need to undergo all the testing ( Tensile + Bend) on heat treated samples i,e after coverting to T6 temper?

By 803056

Date 06-23-2015 14:24

You got it.

By waqasmalik (**)

Date 06-23-2015 14:52

Thanx friend

By waqasmalik (**)

Date 06-23-2015 18:07

Al

I want to ask some questions which are not related to original post.I hope u will not mind to answer those. I shall be greatly thankful to you on this. Questions are regarding standards invoked by design authority on an engineering drawing for aerospace applicatios.

1) MIL-STD-22248A is invoked for welding and MIL-STD-2035SH for weld inspection. Is this valid? 22248A has its own acceptance criteria.So why 2035?

2) In which sort of situation does this 2035 is used. Can it be referred all the times for inspection?

Thanks

By 803056

Date 06-23-2015 19:13

The customer, Owner, person holding the gold, whatever, makes the rules. They can reference any acceptance criteria they feel meets their needs. As long as the requirements are spelled out in the contract documents, all is fair.

This practice is not uncommon. For example: I have a client that designs and manufactures components in accordance with ASME Section I. The material, stainless tubing with a wall thickness of 0.035 inch, is thinner than the undercut allowed by Section I. We modify the visual acceptance criteria and limit the undercut to 10% of the wall thickness.

Best regards - Al