| 摘要 |
The invention relates to steel which is characterised by the following composition as expressed in percentages by weight:-C=0.18 0.30%, -Co=5-7%, -Cr=2-5%, -Al=1-2%, -Mo+W/2=1-4%, -V=trace 0.3%, -Nb=trace 0.1%, -B=trace-50 ppm, -Ni=10.5-15% with Ni>=7+3.5 Al, -Si=trace 0.4%, -Mn=trace 0.4%, -Ca=trace-500 ppm, -Rare earths=trace-500 ppm, -Ti=trace-500 ppm, -O=trace-200 ppm if the steel is obtained by means of powder metallurgy or trace-50 ppm if the steel is produced in air or under a vacuum from molten metal, -N=trace-100 ppm, -S=trace-50 ppm, -Cu=trace-1%, and -P=trace-200 ppm, the remainder comprising iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.
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