Hastalloy

Date 07-08-2007 14:46

hastalloy is harder to weld than stainless. It's similar to Inconel, welding wise. It doesn't flow worth a dern, and has a sort of scum on top of the puddle. Use a 2% tungsten. Have fun...bleh

By pipefitter100 (*)

Date 09-24-2007 01:06

weldhot and fast brother man

By willitfly Date 09-24-2007 02:08

I tig weld and auto weld hast w and hast x just about every day, it's a little sluggish but I think for the most part it welds up OK. just remember clean your material good and on thin material use gas back up.

By ssbn727 (*****)

Date 09-24-2007 02:25 Edited 09-24-2007 04:09

Hi Pipefitter100!

First of all "Weldcome" to the forum!!! :) :) :)

Now as far as welding the Hastelloy hot and fast is concerned, Hastelloy usually should be welded with low to moderate heat input, and it really depends on the specific Alloy, process being used, the rate of cooling which should be slow,and the type of PWHT required so, hot and fast is not to be recommended when it comes to these grades of metal alloys which have alot of Nickel, Chromium and Molybdenum, Iron, and sometimes depending on the specific alloy, small amounts of manganese, cobalt, tungsten, copper, Titanium, Vanadium, Silicon and other trace elements. Wide weaves are not recommended... Stringers are the preferred type of deposits for these alloys.

One more important aspect of welding with these alloys is making darn sure that the BM & FM are really as clean as possible without worrying about trying to save a buck or two by preparing both haphazardly... Otherwise, what you may think is a good weld will actually turn out to be a questionable one with internal discontinuities that more than likely will be rejected depending on their size and what is acceptable according to the referenced code. Here are some websites which will give some information on Hastelloy:

http://en.wikipedia.org/wiki/Hastelloy
http://www.haynesintl.com/pdf/h2019.pdf
http://www.haynesintl.com/
http://www.haynesintl.com/weldinginformation.htm
http://www.haynesintl.com/pdf/h3159.pdf
http://www.haynesintl.com/pdf/h1104.pdf
http://www.haynesintl.com/pdf/h3167.pdf

Btw, beside using a 2% thoriated tungsten, you can also use ceriated and lanthanated tungsten instead. ;)

Respectfully,
Henry

By Tommyjoking (****)

Date 09-24-2007 04:18

look up your process sheets.......depending preheat may be requried and could really be important on avoding cracks....Henry posted some good links. Hastelloy is a more difficult alloy as already mentioned. If not familiar with it...the puddle will look wrong to you....(scum as mentioned)...dont fight it just keep laying it down. Cleanliness and procedure are important to getting good results here....so look that info up before arcing on an expensive part. It is very prone to cracking with sudden heat input or improper heat input.

By Fredspoppy (**)

Date 09-24-2007 11:26

Henry,
On a personal note, your ID as ssbn727 indicates a relationship with the Michigan. When were you on the Michigan? My son-in-law also spent a tour on it.

By js55

Date 09-24-2007 13:59

Henry is right. Hastelloy W (a solution strengthening Ni base alloy alloy) is not to be welded hot and fast. Arc energy and heat input, interpass temps, need to be controlled to minimize the formation of M23C6, and the segregation of corrosion critical elements, typically Fe and Cr from the Ni and Co. This is especially important in mixed reducing/oxidizing atmospheres.
The temptation with all Ni alloys, due to the sluggishness of the puddle has been to crank it up, but in the end this helps very little and is very damaging to the intent of the alloy.
Cleaning prep is critical to minimize the scum (surface oxides-which is where you are getting your scum-don't form as fast on these alloys as say with Al), and widening the bevel helps a great deal.

By ssbn727 (*****)

Date 09-24-2007 17:23

Hi Fredspoppy!

When I was employed for General Dynamics Electric Boat Division in good old "Rotten" Groton, CT I spent the first two to three years helping to build that Lady so, I have a special connection with her... I still know that boat better than most of the master chief's that have served in her!!! however, I no longer can make that claim because, of the conversion the USN made of her as it no longer is classified as a SSBN...

The new designation is SSGN which in essence makes it a Submersible Ship Guided missile Nuclear... Now the insides have been changed so much that I'd probably have to spend some time inside in order to familiarize myself with the changes. Instead of carrying, and being capable of launching 24 Trident D5 II ballistic missiles at our enemies, the converted boomer's will now be capable of handling multiple mission types for which I'm going to defer from commenting because of our nation's war time status...

I can tell you that it will be carrying many, many more of the improved "Tomahawk" cruise missiles than the improved versions of the older "Los Angeles" class fast attack boats which carry many cruise missiles in vertical launch tubes. I believe your son-in -law will understand better as to the changes the USN made, and the changes in it's role as a former "Boomer" ;) All the best to you, your son-in-law, and the rest of your family. :) :) :)

Respectfully,
Henry