essentially 34 in referring to the iron content do not preclude the presence of other elements often present as incidental constituents including deoxidizing and cleansing elements and usual impurities associated therewith in amounts which do not adversely affect the basic characteristics of the alloy manganese silicon calcium and cerium are examples of such constituents in carrying the invention into practice care must be exercised in terms of compositional control for example it has been found that the nickel content must be at least 30 and preferably 32 or more to avoid cracking upon hot working at a level of 25 considerable hot cracking has been experienced upon rolling at 2000 u00b0 f 1093 u00b0 c some edge cracking occurred at the 30 nickel level on the other hand no appreciable benefit has been obtained with nickel contents of say 40 to 45 stress rupture life is not improved thus a nickel range of 32 to 38 particularly 33 to 37 has been found most satisfactory chromium is required for corrosion resistance however excessive chromium can cause a loss in stress rupture strength and lends to the formation of the embrittling sigma phase while up to 21 or 22 chromium can be present for various corrosive environments or where optimum strength is not necessary it is preferred that it not exceed 19 we might add that a level of 15 to 21 has shown to result in a minimum of carburization attack although the over all effect might not be greatly significant in this regard oxidation resistance is not appreciably enhanced with a chromium content of say 20 versus 16 as will be shown infra accordingly a chromium range of 16 to 18 5 is deemed quite advantageous especially when the benefit of the aluminum content is.