| 摘要 |
A steel alloy is disclosed which is suitable for use in parts exposed to extreme stress and wear at high temperatures comprising the following chemical composition in percentage by weight: C 1.5 Si appr 0.7 Mn 2.0 Cr 21.5 Ni 5.0 Mo 0.6 W 1.25 V 2.25 balance iron. A tube piercing mill roller and a tube mill rolling mandrel of said steel are also disclosed. |
