Info needed on ASTM A709 Gr. 70W

Date 03-02-2006 06:41

Hi everybody.

I'm not a regular poster, only a regular reader and I have to mention a lot of my queries have been solved just by browsing thru these postings.
Today, however, I do have a query.

I need some info on the weldability, heat treatment of A709 Gr. 70W steel. We'll be welding thicknesses of up to 150mm (6 in.) and some of the welding would have to be done on site which leaves us with the headache of PWHT on site if required.

I know it is a Group IV material (AWS DI.I) and I have an idea of which consumables to use, but I would like some more info as to welding perimeters, PWHT, chemical analysis and mechanical test requirements.

I've searched AWS, ASTM, AISC websites. I've Googled and I'm still stuck with just the info I got from DI.I

If anybody has welded the stuff before, please help me out.

Thanx

Duncan

By swnorris (****)

Date 03-02-2006 12:26

Duncan,

See if this helps:

http://www.steel.org/AM/Template.cfm?Section=Steel_Q_and_A&TEMPLATE=/CM/ContentDisplay.cfm&CONTENTID=1849

It is important to note that this grade of steel may be susceptable to cracking in the heat affected zone of welds during post weld heat treatment (stress relief) or elevated temperature service. Also, post weld heat treatment or elevated temperature service may degrade heat affected zone toughness. Careful consideration should be given by a competent welding engineer before application.

By Duncan

Date 03-06-2006 08:14

Thanx you very much, SW Norris.

It help a lot and even answered some other questions I had.