Iran
Welcome to the forum!
"Hastelloy" is actually a whole family of alloys.
Try to find out exactly which type of Hastelloy you will be joining and the advice you get will be much more specific.
Examples are Hastelloy X, Hastelloy W, Hastelloy C, Etc.
Here is a free link to Haynes International. They are the patent holders on the Hastelloy group of metals and there is quite a bit of information here too.
http://www.haynesintl.com/cralloys.htm