Used for submerged arc weldings of carbon steel, alloy steel (e. G. 16Mn, etc. ). It features excellent metal mechanics property, stable arc. Convent to remove welding slag, good figuration, can use auto and semi-auto multi-times weld, double surfaces weld, single wire and multi-wire weld at high speed, etc. It has been widely used. It is used or partly used on many key welding structures, such as boilers, vessels of nuclear power stations, pressure vessels, chemical equipment, large and medium spiral tubes, bridges, ships, locomotive vehicles, etc.