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/Hastelloyhttp://www.haynesintl.com/pdf/h2019.pdfhttp://www.haynesintl.com/http://www.haynesintl.com/weldinginformation.htmhttp://www.haynesintl.com/pdf/h3159.pdfhttp://www.haynesintl.com/pdf/h1104.pdfhttp://www.haynesintl.com/pdf/h3167.pdfBtw, beside using a 2% thoriated tungsten, you can also use ceriated and lanthanated tungsten instead. ;)
Respectfully,
Henry