| 摘要 |
PURPOSE:To obtain a steel material for a heat exchanger having superior performance by preparing a steel contg. specified percentages of C, Si, Mn, Cr, Ni, Al, Ca, Y and a rare earth element and having a structure contg. austenite as the principal phase. CONSTITUTION:A steel contg. <=0.2% C, <=2% Si, <=3% Mn, 9-25% Cr, 12- 45% Ni, 4.5-8% Al and one or more among <=0.1% each of Ca, Y and a rare earth element and having a metallic structure contg. austenite as the principal phase is prepd. The steel has superior strength and corrosion resistance at high temp., and when the steel is used, a heat exchanger having very high heat exchange efficiency can be manufactured. To the steel may be added <=5% Cu and/or <=15% in total of one or more among <=5% Mo, <=5% W and <=10% Co.
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