Along with the rise of the coal chemical industry, the conflict between supply and demand of oil is getting relieved.  　

     The coal chemical system contains sulfides, chlorides, hydrides which are very corrosive to metals. Erosion and corrosion are the main causes of leakage of the equipment and pipes that could lead to shut down and accidents. Selecting safe and appropriate materials of pipes and equipment can improve erosion and corrosion resistance, which is increasingly important to ensure the safety of the whole coal chemical system.

　The mechanism of corrosion in coal chemical system is different from hydrogen-induced corrosion in general environment and oxygen absorbing corrosion in neutral solution. Generally, the corrosion in coal chemical industry includes crude gas corrosion, coal tar corrosion, oil absorbing corrosion, cooling water corrosion and gas corrosion, etc.(Super) austenitic, (super) duplex, nickel alloys tubular products manufactured by Jiuli have been widely used in various fields in coal chemical industry.