Method for producing steel composite materials

A method for producing a steel composite characterized by:

• placing at least two steel sheets of different steel grades selected from material 1 and material 2 against each other in an alternating structure;
• hot rolling the steel sheets together, and optionally cold rolling, to create the steel composite;
• and
• diffusion annealing the steel composite at an annealing temperature of 650° C. to 720° C. wherein:
• the annealing temperature is below the minimum of Ac1 temperature of the material 1 and Ac1 temperature of the material 2;
• a chemical potential of the material 1 (μC, material 1) and a chemical potential of the material 2 (μC, material 2) at the annealing temperature correspond to the equation:
• μC, material 1>μC, material 2;
• material 1 has a lower carbon content than material 2, so that an uphill diffusion of carbon takes place between material 1 and material 2;
• material 1 has an alloy composition, in mass percent, of:
• carbon (C):
• 0.02-0.12, manganese (Mn):
• 0.2-1.2, aluminum (Al):
• 0.01-0.07, silicon (Si):
• <0.5, chromium (Cr):
• <0.3, titanium (Ti):
• 0.01-0.15, nitrogen (N):
• <0.02, boron (B):
• <0.02, phosphorus (P):
• <0.01, sulfur (S):
• <0.01, molybdenum (Mo):
• <1, and balance being iron and smelting impurities;
• and
• material 2 has an alloy composition, in mass percent, of:
• carbon (C):
• 0.08-0.6, manganese (Mn):
• 0.8-3.0, aluminum (Al):
• 0.01-0.07, silicon (Si):
• 0.01-0.5, chromium (Cr):
• 0.02-0.6, titanium (Ti):
• 0.01-0.08, nitrogen (N):
• <0.02, boron (B):
• 0.002-0.02, phosphorus (P):
• <0.01, sulfur (S):
• <0.01, molybdenum (Mo):
• <1, and balance being iron and smelting impurities.