http://www.weldmongerstore.com/
http://www.weldingtipsandtricks.com/carbon-steel.html
Welding Low Alloy Metal often goes higher with a preheat. Carbon content material is the primary issue to think about in how a lot preheat to make use of… There’s something referred to as a “carbon equal system” that takes under consideration parts apart from carbon that contribute to hardening. For instance 4130 chromoly has a carbon content material of .30 p.c however has a carbon equal of .60 p.c.
source