what does 7018 mean on a welding rod_aws e6013 welding electrode specification

DingZhou JinLong Metal Production Co. , Ltd. is one of the largest integrated manufacturers of special welding materials in China. Its main products include stainless steel welding materials, heat resistant steel welding materials, low temperature steel welding materials, high strength steel welding materials, hardfacing welding materials, nickel-based cast iron welding materials, nickel and nickel alloy welding materials, copper and copper alloy welding materials, special purpose welding materials, etc. , more than 200 varieties with an annual production capacity of 20,000 tons. Products with good market applicability and competitiveness, widely used in petrochemical, chemical, nuclear power, power, light industry machinery, metallurgy and pressure vessel manufacturing industries. Sales network throughout the country, has become a domestic special welding materials one of the mainstream brands, a good reputation for cooperation, to the industry widely praised.