Corrosion resistant ferritic stainless steel

Claim 2

A steel in accordance with claim 2 in which the chromium content is from 22 to 28 percent.

Claim 3

A steel in accordance with claim 2 in which metal from the group consisting of titanium, vanadium and columbium is present in an amount of at least 0.15 percent.

Claim 4

A steel in accordance with claim 4 in which at least the element titanium is present.

Claim 5

A steel in accordance with claim 2 containing 18 to 22 percent chromium, about 5 to 10 percent molybdenum, up to about 1.5 percent silicon, a nickel content of about 2.5 to 6 percent, at least 0.2 percent of at least one metal from the group consisting of titanium, vanadium and columbium when the steels are produced by aiR melting, up to 0.5 percent aluminum, carbon present up to 0.06 percent and the balance essentially iron.

Claim 6

A steel in accordance with claim 6 in which the ''''CMS'''' indicator is at least 41 percent.

Claim 7

A steel in accordance with claim 2 containing from 22 to 28 percent chromium, about 3.5 to 8 percent molybdenum, up to about 1.5 percent silicon, a nickel content of about 2.5 to 6 percent, at least 0.2 percent of metal from the group consisting of titanium, vanadium and columbium when the steels are produced by air melting, up to 0.5 percent aluminum, carbon present up to 0.06 percent and the balance essentially iron.

Claim 8

A steel in accordance with claim 8 in which the ''''CMS'''' indicator is at least 41 percent.

Claim 9

A steel in accordance with claim 1, which has been subjected to a final annealing treatment over a temperature range of about 1,900*F. to 2,200*F.

Claim 10

A stainless steel containing from 16 to 30 percent chromium, from about 0.5 up to about 11 percent molybdenum, up to 3 percent silicon, with the provisos that the ''''CMS'''' indicator represented by the sum of the chromium plus three times the amount of molybdenum plus three times the percentage of silicon is not less than 34 percent, nor above about 48 percent where good workability is desired, from 2 to about 8 percent nickel, up to less than 2 percent titanium, up to about 2 percent vanadium and up to about 2 percent columbium, with at least one element from the group consisting of titanium, vanadium and columbium being present in a small but effective amount to enhance the corrosion resistance in respect of steels produced by air melting and in which the ''''CMS'''' indicator is not above 38 percent, the sum total of titanium, vanadium and columbium not exceeding about 4 percent, carbon up to 0.1, up to 2 percent aluminum, up to about 2 percent manganese, up to about 10 percent cobalt, up to about 4 percent tungsten, and the balance essentially iron.

Claim 11

A steel in accordance with claim 2 in which carbon above about 0.06 percent is fixed.

Claim 12

A steel in accordance with claim 12 in which carbon above about 0.02 percent is fixed.