Method for making an abrasion-resistant steel plate and plate obtained

A plate of abrasion-resistant steel, the composition of said steel consisting of (by weight percent):

• 0.45%≦C≦0.8%;
• 0%≦Si≦2% and
• 0.025%≦Al≦2%,
• wherein 0.35%≦Si+Al≦2%;
• 0%≦Mn≦2.5%;
• 0%≦Ni≦5%;
• 0%≦Cr≦5%;
• 0%≦Mo≦0.50% and
• 0%≦W≦1.00%,
• wherein 0.1%≦Mo+W/2≦0.50%;
• 0%≦B≦0.02%;
• 0%≦Ti≦2% and
• 0%≦Zr≦4%,
• wherein 0.05%≦Ti+Zr/2≦2%;
• N≦0.03%
• optionally from 0% to 1.5% of copper,
• optionally at least one element selected from Nb, Ta, and V at contents such that Nb/2+Ta/4+V≦0.5%,
• and the balance being iron and impurities resulting from the production operation,
• wherein the chemical composition of said steel further complying with the following relationships:
• 0.1%≦C−Ti/4−Zr/8+7×N/8 0.55%,
• Ti+Zr/2−7×N/2≧0.05%, and
• 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)1/2+K>1.8, wherein
• K=0.5 if B≧0.0005% and K=0 if B<0.0005%,
• said steel having a martensitic or an admixture of martensitic and bainitic microstructure,
• said steel further containing from 5% to 20% of retained austenite microstructure and
• said steel further containing coarse titanium carbides or coarse zirconium carbides
• said steel having a hardness from 580 HB to 650 HB;
• and,
• said plate having a surface evenness characterized by a deflection of less than 12 mm/m.