| 摘要 |
<p>The invention concerns a calcium-treated steel alloy, wherein the hardenability effect of boron is combined with an improved machinability. The chemical composition of the steel in percentages by weight is 0.01 - 0.5% carbon, 0.01 - 2.0% silicon, 0.4 - 1.6% manganese, 0.01 - 0.3% sulphur, 0 - 2.0% chromium, 0 - 0.8% molybdenum, 0.002 - 0.02% boron, 0 - 0.015% titanium, 0.005 - 0.014% aluminium, 0.0015 - 0.01% calcium and in addition B = (0.5 - 2) x (N - Ti/3.4), wherein B is the boron content, N the nitrogen content and Ti the titanium content in percentages by weight.</p> |
