Edge formability in metallic alloys

A method for improving the hole expansion ratio in a metallic alloy that had undergone a hole expansion ratio loss as a consequence of forming a hole wherein with a sheared edge comprising:

• a. supplying a metal alloy comprising at least 50 atomic % iron and at least four elements selected from Si, Mn, B, Cr, Ni, Cu or C and melting said alloy and cooling at a rate of ≤250 K/s or solidifying to a thickness of ≥2.0 mm up to 500 mm and forming an alloy having a Tm and matrix grains of 2 μm to 10,000 μm;
• b. heating said alloy to a temperature in a range of 700° C. to below said Tm and at a strain rate of 10−6 to 104 and reducing said thickness of said alloy and providing a first resulting alloy having a tensile strength of 921 MPa to 1413 MPa and an elongation of 12.0% to 77.7%;
• c. stressing said first resulting alloy and providing a second resulting alloy having a tensile strength of 1356 MPa to 1831 MPa and an elongation of 1.6% to 32.8%;
• d. heating said second resulting alloy to a temperature of in a range of at least 400° C. and below said Tm and forming a third resulting alloy having matrix grains of 0.5 μm to 50 μm and forming a hole therein with shearing wherein said hole has a sheared edge and has a first hole expansion ratio (HER1);
• e. heating said third resulting alloy with said hole and associated HER1 wherein said third resulting alloy indicates a second hole expansion ratio (HER2) wherein HER2≥HER1.

A method for improving the hole expansion ratio in a metallic alloy that had undergone a hole expansion ratio loss as a consequence of forming a hole with a sheared edge comprising:

• a. supplying a metal alloy comprising at least 50 atomic % iron and at least four elements selected from Si, Mn, B, Cr, Ni, Cu or C and melting said alloy and cooling at a rate of ≤250 K/s or solidifying to a thickness of ≥2.0 mm up to 500 mm and forming an alloy having a Tm and matrix grains of 2 μm to 10,000 μm;
• b. heating said alloy to a temperature in a range of 700° C. to below said Tm and at a strain rate of 10−6 to 104 and reducing said thickness of said alloy and providing a first resulting alloy having a tensile strength of 921 MPa to 1413 MPa and an elongation of 12.0% to 77.7%;
• c. stressing said first resulting alloy and providing a second resulting alloy having a tensile strength of 1356 MPa to 1831 MPa and an elongation of 1.6% to 32.8%;
• d. heating said second resulting alloy to a temperature below said Tm and forming a third resulting alloy having matrix grains of 0.5 μm to 50 μm wherein said third resulting alloy has a first hole expansion ratio (HER1) of 30 to 130% for a hole formed therein without shearing;
• e. forming a hole in said third resulting alloy, wherein said hole is formed with shearing and has a second hole expansion ratio (HER2) wherein HER2=(0.01 to 0.30)(HER1);
• f. heating said third resulting alloy wherein the HER2 recovers to a value HER3, and HER3=(0.60 to 1.0) HER1.

A method for punching one or more holes in a metallic alloy comprising:

• a. supplying a metal alloy comprising at least 50 atomic % iron and at least four elements selected from Si, Mn, B, Cr, Ni, Cu or C and melting said alloy and cooling at a rate of ≤250 K/s or solidifying to a thickness of ≥2.0 mm up to 500 mm and forming an alloy having a Tm and matrix grains of 2 μm to 10,000 μm;
• b. heating said alloy to a temperature in a range of 700° C. to below said Tm and at a strain rate of 10−6 to 104 and reducing said thickness of said alloy and providing a first resulting alloy having a tensile strength of 921 MPa to 1413 MPa and an elongation of 12.0% to 77.7%;
• c. stressing said first resulting alloy and providing a second resulting alloy having a tensile strength of 1356 MPa to 1831 MPa and an elongation of 1.6% to 32.8%;
• d. heating said second resulting alloy to a temperature in a range of at least 400° C. to below said Tm and forming a third resulting alloy having matrix grains of 0.5 μm to 50 μm and having an elongation (E1);
• e. punching a hole in said third resulting alloy at a punch speed of greater than or equal to 10 mm/second wherein said hole has a hole expansion ratio of greater than or equal to 10%.