T-1 equivilent to ASTM A514? 2

[metman]

It has been too many years so not sure if memory serves.

As I recall, T-1 is a US Steel trade name for a high strength low alloy (HSLA) constructional steel plate.

ASTM A514 is the designation that comes to mind which includes the composition for T-1.

If 514 is the correct ASTM number, there is a table of alloys within the spec and one or more of these alloys are susceptible to brittle failure if thermally stress relieved. I believe it was with reference to certain concentrations of Titanium and/or other alloying elements.

Because of thread330-263985 I was concerned that if someone here is not familiar with this embrittling phenomena of some of these HSLA materials and if T-1 is one of them that a post-weld thermal treatment might fall into the unwanted temperature range.

Will someone with access to ASTM specs please confirm or deny my concern?

 

[unclesyd]

Here is an answer grade for grade.

A 514-65 VS. A 514-00A

A 514-65 differs from A 514-00a at dozens of points. Table B–6 summarizes the substantial ones. Unlike standards such as A 36, which have simple, non-proprietary chemistry requirements, each variant chemistry in A 514 represents a single mill’s 100 ksi steel. For instance, Brockenbrough and Johnson (1968) identify A 514 Grade F as USS T1, A 514 Grade B as USS T1 Type A, and A 514 Grade H as USS T1 Type B.

page 83:

http://wtc.nist.gov/pubs/NISTNCSTAR1-3ADraft.pdf

 

[fredt]

The main characteristic of T1 is that it is a quench and tempered steel. It gets its properties from heat treatment rather than alloying. There are a large number of international equivalents from Europe, Scandanavia, Japan and here in Australia. The steel is readily weldable and can be post weld heat treated or stress relieved but at a lower temperature than mild steel. A suitable stress relieve temperature is 580C +/-10C

 

[RPRad]

Hi Folks

Had an opportunity to talk to a fella from USS Steel a few years back, he indicated that unless required specifically by Code to avoid PWHT of these materials if possible, they are apparently very susceptible to grain boundary embrittlement...especially the older plate material. He also indicated that the effect is cumulative, that is to say that it gets worse with each PWHT cycle the material undergoes...so it may not fail after the first PWHT cycle but you could have significantly decreased toughness in the HAZ.

We had a situation several years ago where it was impossible to weld repair the material as it kept cracking about 24 - 48 hrs after PWHT. The material was preheated during welding,MPI and Radiographed after welding and before PWHT, no cracks were found...but after PWHT we never were able to do the MPI or Radiography as it had already cracked.

I believe some grades are more susceptible than others, there have been several papers published by USS Steel on the topic, unfortunately I dont know where the ones I had are now. A real eye opener to read...

 

[metman]

Thank you RPRad
I could not open or download the link provided by unclesyd vis:

http://wtc.nist.gov/pubs/NISTNCSTAR1-3ADraft.pdf

But I am thinking that the spec might even include the warning about PWHT and Thermal Stress Relief for the particular culprit alloys.

 

[unclesyd]

Sorry that link didn't work for you as it still works for me.

I think here is all the information you will ever need for your project with T1 or 514

http://www.arcelormittal.com/platei...chure/ARCELORMITTAL A514 AND T-1_20080514.pdf

http://www.arcelormittal.com/platei...ts/Applications/ARCELORMITTAL HOW TO WELD.pdf

 

[metman]

unclesyd,
Thanks Good links.
I tried to copy and paste but the file will not allow copying.
In the first link, each and every Grade of either A514 or T-1 has one or the other of two footnotes (one crusifix or two crusifix):
one crusifix = PWHT may degrade strength and toughness...
two crusifix = ...may be susceptible to cracking in the heat affected zone of the welds during post-weld heat treatment (stress relief).

In the second link near the bottom:

Rule 4: Use caution in applying PWHT...several paragraphs delineaing the ill effects of PWHT i.e. cracking, brittleness..

In essence the steel supplier is recommending to not PWHT

This is not a project of mine. Please refer to the OP and
thread330-263985: Welding 4140 to T-1 high tensile steel

My concern was that I saw no recommendations about PWHT on that thread -- but, I just re-read the Origianl Posting at the above thread which included the comment:

We can't reheat treat this joint after welding.

so I guess I beat that dead horse well beyond its second death! I suppose overkill would be more succinct.