The Ethylene Cracking Furnace Tube Weld Seam Sulfur Corrosion Countermeasures Research

The weld seams on HP40Nb furnace tube of ethylene cracking furnace of a petrochemical enterprise often fail because of sulftur corrosion.This paper is to improve corrosion resistance of weld seam by adjust element composition.The composition of weld seam is designed to be the same as the parent material and small amount of Al or rare earth element is added to the weld seam.Weld joints are made.Corrosion resistance is verified by sulfur vapor corrosion test.By means of metallographic inspection,SEM and EDS,corrosion resistance is evaluated and corrosion mechanism is discussed.Room temperature tensile test,high temperature short-term tensile test,high temperature creeping test are performed with the weld joints.The corrosion test results show that the corrosion resistance is improved and corrosion rate of the weld seam with higher concentration of Al is the lowest.The mechanical test results show that mechanical properties are better than or close to that of the original one.The weld seams satisfy the requirement of service.The research is of great value.