| 摘要 |
PURPOSE:To obtain the steel having corrosion resistance to sea water and H2S and additionally superior mechanical properties by the following method in which after the steel containing C, Si, Mn, Cr, Ni, Mo, V and N in predetermined proportions has been subjected to solution treatment, it is rapidly cooled and then tempered. CONSTITUTION:The steel containing C; 0.05-0.15wt%, Si; less than 0.5wt%, Mn; 0.5-1.5wt%, Cr; 14-17wt%, Ni; 3.0-6.0wt%, Mo; 2.0-3.5wt%, V; 0.05- 0.15wt%, N; 0.05-0.18wt%, balance; Fe and unavoidable impurities, is heat-treated as follows. Namely, this steel is heated at 1,000-1,100 deg.C, especially at 1,040- 1,060 deg.C and is rapidly cooled after solution treatment has been achieved. In this case, especially the range of 900-500 deg.C is preferably for rapid cooling. Next, the steel having been cooled rapidly is tempered at 250-550 deg.C, especially at 400- 500 deg.C. Thus the steel with superior properties in strength, toughness and corrosion resistance may be produced cheaply. |
