Hello is a heat-resistant steel electrode 15CrMo a 12CrMoV welding base metal is not the same as   R307 heat-resistant steel electrodes meet the GB E5515-B2 is quite AWS E8015-B2       Description: low-hydrogen type pearlitic heat-resistant steel electrodes, DCRP, all-position welding, before welding to be preheated to 160 ℃ -250 degrees Celsius. The welding temperature below 520 ℃ Cr1%-Mo0.5% pearlitic heat-resistant steel (15CrMo, etc.) welding, boiler tubes, pressure vessels, oil refining equipment, etc., can also be used to weld 30CrMnSi cast. Grade: R317 Model: E5515-B2-V Characteristics: low hydrogen sodium type molybdenum 0.5%, 1% chromium, vanadium pearlitic heat resistant steel electrode, DC reverse, all-position welding, preheat to 250 to 300 ℃. Purposes: for the working temperature of 540 ℃ pearlitic heat resistant the steel (12CrMoV), such as high temperature and high pressure boiler tube, oil cracking equipment, high-temperature synthetic chemical mechanical equipment. Material (chemical composition of the deposited metal): C ≤ 0.12 Mn 0.50 ~ 0.90 Cr 1.00 ~ 1.50 Mo 0.4 ~ 0.65 Other V 0.10 ~ 0.35