Abstract: Disclosed herein is method of manufacturing an automobile part having different local strengths, more particularly, a method of manufacturing an automobile part using a steel sheet subjected to heat-treatment hardening and having different local thicknesses. The method includes preparing blank sheets using steel sheets subjected to heat-treatment hardening and having different thicknesses or different material properties according to desired strength; forming a blank assembly by joining the blank sheets to each other via laser welding; cold-pressing the blank assembly; and heating the cold-pressed part to a temperature of AC3 or more, followed by quenching the cold-formed part received within dies to remove residual stress while increasing strength of the automobile part.

Abstract: The present invention relates to a separator plate for a fuel cell and to a method for producing the same, and relates to an invention wherein a surface-modification layer is formed through the use of low temperature plasma processing such that it is possible to prevent the hydrophobic characteristics which occur during gasket forming and to have outstanding hydrophilic characteristics, and such that it is possible to obtain the advantageous effect of highly outstanding corrosion resistance and electrical conductivity not only initially but also even after long-term use in a fuel-cell operating environment, and also such that it is possible to maintain outstanding durability even when using a normal low-price stainless-steel sheet base material, and it is possible to reduce the unit cost of production of the separator plate for the fuel cell since surface processing can be carried out at low cost.

Abstract: The present invention relates to a separator plate for a fuel cell and to a method for producing the same, and relates to an invention wherein a surface-modification layer is formed through the use of low temperature plasma processing such that it is possible to prevent the hydrophobic characteristics which occur during gasket forming and to have outstanding hydrophilic characteristics, and such that it is possible to obtain the advantageous effect of highly outstanding corrosion resistance and electrical conductivity not only initially but also even after long-term use in a fuel-cell operating environment, and also such that it is possible to maintain outstanding durability even when using a normal low-price stainless-steel sheet base material, and it is possible to reduce the unit cost of production of the separator plate for the fuel cell since surface processing can be carried out at low cost.

Abstract: Disclosed herein is method of manufacturing an automobile part having different local strengths, more particularly, a method of manufacturing an automobile part using a steel sheet subjected to heat-treatment hardening and having different local thicknesses. The method includes preparing blank sheets using steel sheets subjected to heat-treatment hardening and having different thicknesses or different material properties according to desired strength; forming a blank assembly by joining the blank sheets to each other via laser welding; cold-pressing the blank assembly; and heating the cold-pressed part to a temperature of AC3 or more, followed by quenching the cold-formed part received within dies to remove residual stress while increasing strength of the automobile part.