Metal corrugated expansion joints for steel mills and smelters are mainly installed and used in high-temperature, medium-temperature and low-temperature hot air ducts, smoke and air ducts and high-frequency mechanical vibration duct parts. Corrugated metal expansion joints have the characteristics of good flexibility, corrosion resistance, high temperature resistance, wear resistance and long fatigue life, and can absorb axial, lateral and three-way displacement of the pipeline.