I just did an internet search and found around 10 pages (maybe more) on AISI 4130 and many of them addressed welding issues.

You provided few specifics in your post, so I guess the best I can do is to suggest reading some of the articles availble on the internet. You can then form your own conclusions as to the best approach to take to weld whatever it is that you are trying to weld.

Best regards - Al

D1.1 Clause 1 subclause 1.2 Limitations
The code was specifically developed for welded steel structures that utilize carbon or low alloy steel that are 1/8 in or thicker with a minimum specified yield point of 100 ksi or less.
What is the structure or product and what is its thickness would narrow down the code needed/used.

ggarso2000 are you doing this for yourself or a customer . If for a customer that should be his call or should be on the print,even the preheat, but it depends on the appacation.

                    M.G.