R302 heat-resistant steel welding rod, 
 R307 heat-resistant steel electrode characteristics and uses; R302 titanium calcium type electrode. R307 is a low hydrogen sodium type coating. Can be all-position welding, preheating before welding to be 160-200 ℃, after welding, to go through 675-705 ℃ tempered. Can be used for welding at 520 ℃ temperature below 1% Cr-0.5% Mo heat resistant steel, such as boiler tubes, pressure vessels, oil refining equipment, but the R302 is mainly used to cover up welding electrode. 


 R312 heat-resistant steel electrode 
 R310 heat-resistant steel welding rod, 
 R317 heat-resistant steel electrode characteristics and uses; R310 is a type of titanium oxide coated electrodes can be AC and DC, the weld has a good performance and resistance to cold plastic holes. R312 titanium calcium type electrode, mainly used to cover up the pipe welding. R317 is a low hydrogen type coated electrode, the use of DC power. Three electrodes are suitable for all position welding, preheating before welding to be 250-300 ℃, after welding, to go through 715-745 ℃ tempered. Can be used for welding temperature below 540 ℃ pearlitic heat-resistant steel.