摘要 |
A heat-formable, ferritic steel alloy having 20 to 25% of chromium, 5 to 8% of aluminium, not more than 0.01% of phosphorus, not more than 0.01% of magnesium, not more than 0.5% of manganese and not more than 0.005% of sulphur, the remainder being iron, including unavoidable impurities, is proposed, according to the invention the said alloy furthermore containing 0.03 to 0.08% of yttrium, 0.004 to 0.008% of nitrogen, 0.02 to 0.040% of carbon and about equal amounts of 0.035 to 0.07% of titanium and 0.035 to 0.07% of zirconium, with the proviso that the sum of the contents of titanium and zirconium in percent is 1.75 to 3.5 times as large as the sum of the contents of carbon and nitrogen in percent. The alloy has substantially better properties in use than the base alloy. |