R317 comply with GB E5515-B2-V Note: R317 is a low hydrogen sodium type of Cr1%-Mo0.5%-V pearlitic heat resistant steel welding rod, DC reverse, all-position welding. Weldment should be based on the structural characteristics of a proper warm-up and weld heat treatment.   Purposes: pearlitic heat resistant steel for welding temperature below 540 ℃ (12CrMoV) structure, such as high temperature and high pressure boiler tube, oil cracking equipment, high-temperature synthesis of chemical equipment. R327 comply with GB E5515-B2-VW Note: R327 is a low hydrogen sodium type CrMoVW pearlitic heat-resistant steel electrodes, DC reverse, all-position welding. Weldment should be based on the structural characteristics of a proper warm-up and weld heat treatment.   Uses: used to the welding temperature below 570 ℃ 15CrMoV pearlitic heat resistant steel. Basically correct, but to pay attention to Before welding electrodes should be baked 1h after about 350 ℃, with the drying with. Weldment rust, oil, water and other impurities must be removed before welding.