A hot rolled plate or forging of an austenitic steel not susceptible to relaxation cracking is provided. The hot rolled plate or austenitic steel includes a composition having in percentages by weight: 0.019%≤C≤0.030%, 0.5%≤Mn≤2%, 0.1%≤Si≤0.75%, Al≤0.25%, 18%≤Cr≤25%, 14%≤Ni≤17%, 1.5%≤Mo≤3%, 0.001%≤B≤0.008%, 0.25%≤V≤0.35%, 0.23%≤N≤0.27%, the balance being iron and unavoidable impurities, Ni(eq.)≥1.11 Cr(eq.)−8.24, Cr(eq)=Cr+Mo+1.5Si+5V+3Al+0.02, Ni(eq)=Ni+30C+x(N−0.045)+0.87; x=30 for N≤0.2, x=22 for 0.2