CAST STEEL FOR WATER TURBINE FOR SEAWATER PUMP

摘要

PURPOSE:To obtain the titled cast steel with high toughness and superior corrosion fatigue strength by using 15Cr-6Ni-2Mo martensitic cast steel as Cr-Ni-Mo cast steel. CONSTITUTION:This martensitic cast steel consists of, by weight, 0.02-0.07% C, 0.2-0.6% Si, 0.3-0.8% Mn, 4.5-7% Ni, 14.5-16.5% Cr, 1.5-3% Mo and the balance Fe and contains ferrite and austenite. The cast steel has higher toughness than 14Cr-5Ni-1Mo-0.25Nb cast steel for a propeller, and it is superior to 13Cr-15Ni-1.5Mo cast steel in corrosion fatigue strength and has superior resistance to corrosion by seawater and superior weldability. Accordingly, when the cast steel is used as the material of the runner and guide vane of a water turbine for a large-sized seawater pump for the power generation, it is advantageous to reliability and economical efficiency.