摘要 |
A steel alloy comprising from: (a) 0.6 to 0.9 wt. % carbon, (b) 0.1 to 0.5 wt. % silicon, (c) 0.1 to 1.5 wt. % manganese, (d) 1.5 to 2.0 wt. % chromium, (e) 0.2 to 0.6 wt. % molybdenum, and up to: (f) 0.25 wt. % nickel, (g) 0.3 wt. % copper, (h) 0.2 wt. % vanadium, (i) 0.2 wt. % cobalt, (j) 0.2 wt. % aluminium, (k) 0.1 wt. % niobium, (l) 0.2 wt. % tantalum, (m) 0.05 wt. % phosphorous, (n) 0.03 wt. % sulphur, (o) 0.075 wt. % tin, (p) 0.075 wt. % antimony, (q) 0.075 wt. % arsenic, (r) 0.01 wt. % lead, (s) 350 ppm nitrogen, (t) 100 ppm oxygen, (u) 50 ppm calcium, (v) 50 ppm boron, (w) 50 ppm titanium, the balance iron, including any other unavoidable impurities, wherein the alloy comprises molybdenum and silicon in a weight ratio of 0.4≦̸Mo/Si≦̸6.0 and comprises molybdenum and chromium in a weight ratio of 0.1≦̸Mo/Cr≦̸0.4. |