There is enough pickup of alloy from the base material to give the required tensile strength in the as welded condition.
Welding rod for 4130 steel.
A pre heat of 300 f 350 f is required for some of the higher carbon grades to prevent cracking.
Some fabricators prefer to use austenitic stainless steel fillers to weld 4130 tubing.
On multiple pass welds cro mo alloy electrodes are usually specified.
Other stainless steel filler metals can cause cracking and stainless steel filler metal is more expensive.
This is acceptable provided 310 or 312 stainless steel fillers are used.
Smaller 4130 parts like below are sometimes tig welded with 4130 rod so they can be heat treated after welding a tig finger heatshield is great for welding 4130 chromoly tubing click on the image below to learn more have you ever tried to bend a piece of 4130 chromoly tubing.
Other stainless steel fillers can cause cracking.
Successfully welding 4130 requires preserving its mechanical properties by heating and cooling the weld in a controlled manner.
What consumable can be used to weld on sae 4130 steel tubing.
Sae 4130 aisi 4130 sae4130 is a low alloy copper coated wire designed for the welding of heat treatable low alloy steels such as the sae aisi 4100 or 8630 series as well as steel castings with similar hardening characteristics.
Stainless filler material is typically more expensive.
Fortunately the gtaw process provides sufficient heat control.
On light chrome moly tubing mild steel electrodes are commonly used.