Single values shown are maximum. Ni, Cr, Mo and V may be present but are not intentionally added. The maximum weight of copper due to any coating plus the residual copper content in the steel shall be 0.50. Adding argon to CO 2 will benefit. Ar is popularly used for short circuiting transfer in welding mild steels.
Spatter is minimized.
CO 2 also, on both mild and low alloy steels. Reverse Polarity is never used. Shielding - Argon. In some instances, the addition of helium might be considered for deeper penetration or on large sections, but He-Ar or He are generally restricted to automatic welding. File Test to Estimate Hardness of Steel Approx.