Method of producing a sheet steel product such as a reinforcement element in a larger structure
AssigneeSSAB Hardtech AB
InventorErland Lundstrom
Life of this patent
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Abstract
A product of sheet steel is formed in a pair of cooled tools when hot and is then hardened to a martensitic structure while still in the tools. In this manner, the tools function as a fixture while the steel is hardening. The steel is kept mild in the areas in which it is to be machined, for example punched. Inserts in the tools are used to prevent rapid cooling of the steel sheet and thereby a martensitic structure in the areas adjacent the inserts. The same effect can be obtained by recesses in the tools so that there will be a gap between the sheet steel and the tools.
Claims18
A method of making a sheet steel product comprising the steps of:
- providing a steel sheet of a given size;
- providing a tool for holding the steel sheet;
- positioning the steel sheet in the tool;
- heating the steel sheet to an austenitizing temperature;
- hot forming a steel sheet product out of the steel sheet while using the tool;
- hardening at least a portion of the steel sheet product to a hardness;
- producing at least one mild area in the steel sheet product, the mild area having a hardness substantially less than the hardness of the hardened portion of the steel sheet product;
- and
- forming the at least one mild area in the steel sheet product.
A method of making a sheet steel product comprising the steps of:
- providing a steel sheet of a given size;
- providing a tool for holding the steel sheet;
- positioning the steel sheet in the tool;
- heating the steel sheet to an austenitizing temperature;
- hot forming a steel sheet product out of the steel sheet while using the tool;
- hardening at least a portion of the steel sheet product to a hardness;
- yielding at least one mild area in the steel sheet product substantially simultaneously with the step of hardening at least a portion of the steel sheet product, the mild area having a hardness substantially less than the hardness of the hardened portion of the steel sheet product;
- and
- forming the at least one mild area in the steel sheet product.
Dependencies are inferred from the claim text.