Alloy based on iron, containing nickel, chromium and aluminium, and process for obtaining same

Claim 1

AN ALLOY CONSISTING ESSENTIALLY OF IRON, NICKEL, CHROLMIUM AND ALUMINIUM, THE PROPORTION BY WEIGHTIN THE ALLOY OF NICKEL AND CHROMIUM CORRESPONDING TO THE AREA ABCDE IN THE FIG. 3 OF THE ACCOMPANYING DRAWINGS, THE ALUMINIUM CONTENT BY WEIGHT BEING OF 1 TO 6% AND THE MAXIMUM CARBON CONTENT BEING 0.15% INCLUDING AS POSSIBLE COMPONENTS SI, TI, MO AND MN IN WHICH THE SUM CR+1.5 SI+2.5 AL+2.5 TI+ 098 MO-NI-12 C-0.2 MN IS AT THE MOST EQUAL TO 10, THE BALANCE BEING IRON, SAID ALLOY BEING FREE OF $ FERRITE AND SUSCEPTIBLE TO ANNEALING AT 750*C. TO 1250*C. AND QUENCHING THROUGH PHASE TRANSFORMATION TO A SUBSTANTIALLY ALUMINUM-SOLUBEL MARTENSITE-LIKE STRCTURE AND THEREAFTER TO PRECIPITATION HARDENING AT FROM 200*C. TO 700*C. BY AN ALUMINIUM RICH COMPOUND, THE COMPONENT NI+30 C+0.5 MN BEING SUBSTITUTABLE FOR NI AND THE COMPONENT CR+MO BEING SUBSTITUTABLE FOR CR, MN THEN HAVING A MAXIMUM VALUE OF 4% AND MO HAVING A MAXIMUM VALUE OF 4.5%.