... treatment is applied to prevent fatigue crack.Crank shaft (material used: 35CrMo, 4140,1045,QT800)Nitrogen hardening treatment is applied ... strength, high hardness, durable and corrosion resistant feature.Plunger (material used: superior ceramic, Colmonoy coated,Tungsten carbide coated wear resistant and ... to the users. CO2 injection pump,CO2 supercritical extraction pumps,CO2 transportation pump