Belongs martensitic heat resistant steel at 800 ℃ has good oxidation resistance. Compared with 1Cr5Mo steel, Si volume containing more than 1.5%, so increasing tendency to temper brittleness of steel, will produce parts to work long hours at a high temperature brittleness breaking. The steel in sulfur-oxidizing atmosphere and heat the oil medium, good corrosion resistance. After normalizing, after heat treatment have a higher rupture strength and creep strength. The steel quenching phenomenon free, after thermal processing, such as cooling too quickly, it will crack occurred, should slow cooling. Poor weldability, can be welded, not welding, before welding to be preheated to 300 ℃ ~ 400 ℃, 750 ℃ ??were tempered after welding. Boiler and economizer hanger ≤700 ℃ operating temperature of the pipe clamp