Metal sheet with tailored properties

Abstract

Moving metal strips can be heat treated with any number or combination of dimensionally variable tempers across widths, lengths, or thicknesses of a metal strip. To provide dimensionally variable heat treatment, an apparatus can include one or more heating units suitable to increase the temperature of a metal strip moving proximate the apparatus to a heat treatment temperature. The apparatus can also include one or more cooling units positioned near the heating units to absorb heat and cool the metal strip to minimize the amount of heat transferred from a first region of the metal strip that is to be treated to a second region of the metal strip that is not to be treated.

What is claimed is: 
     
         1 . A metal processing system, comprising:
 a dimensionally variable heat treatment apparatus having an opening for accepting a metal article moving in a processing direction, the heat treatment apparatus including:
 a heating unit positionable proximate the metal strip on a first side of a separation plane intersecting the metal strip to raise a strip temperature of a first portion of the metal strip on the first side of the separation plane at or above a heat treatment temperature; and 
 a cooling unit positionable proximate the metal strip on a second side of the separation plane to maintain a second portion of the metal strip on the second side of the separation plane below the heat treatment temperature. 
   
     
     
         2 . The system of  claim 1 , wherein the separation plane is parallel the metal strip, wherein the heating unit extends across a width of the metal strip proximate the first side of the separation plane, and wherein the cooling unit extends across the width of the metal strip proximate the second side of the separation plane. 
     
     
         3 . The system of  claim 1 , wherein the separation plane is parallel a longitudinal axis of the metal strip and perpendicular a top surface of the metal strip, wherein the heat treatment apparatus further includes:
 an additional heating unit positionable proximate the metal strip on the first side of the separation plane and opposite the metal strip from the heating unit; and   an additional cooling unit positionable proximate the metal strip on the second side of the separation plane and opposite the metal strip from the cooling unit.   
     
     
         4 . The system of  claim 1 , wherein the heating unit has sufficient heat generation power and has a sufficient length to maintain the strip temperature of the metal strip at or above the heat treatment temperature for a sufficient duration for tempering the metal strip. 
     
     
         5 . The system of  claim 1 , further comprising a linear actuator coupled to the dimensionally variable heat treatment apparatus to laterally adjust the heating unit and cooling unit with respect to the metal strip to move the separation plane with respect to the metal strip. 
     
     
         6 . The system of  claim 5 , further comprising a controller coupled to the linear actuator to laterally adjust the heating unit and the cooling unit as a function of longitudinal distance along the metal strip. 
     
     
         7 . The system of  claim 1 , further comprising an additional dimensionally variable heat treatment apparatus having an additional heating unit and an additional cooling unit positioned proximate the metal strip on opposite sides of an additional separation plane, wherein the additional dimensionally variable heat treatment apparatus is spaced apart from the dimensionally variable heat treatment apparatus, and wherein the additional separation plane is not coplanar with the separation plane. 
     
     
         8 . The system of  claim 1 , wherein the separation plane is not parallel a lateral cross section of the metal strip. 
     
     
         9 . A method for variably heat treating a metal strip across a dimension of the metal strip, the method comprising:
 passing a moving metal strip through a dimensionally variable heat treatment apparatus having a heating unit and a cooling unit positioned on opposite sides of a separation plane;   heating a first portion of the moving metal strip by the heating unit, wherein heating the first portion includes raising a strip temperature of the first portion of the moving metal strip at or above a heat treatment temperature for a duration; and   cooling the moving metal strip by the cooling unit, wherein cooling the moving metal strip includes removing heat from the moving metal strip adjacent the first portion sufficiently to maintain a temperature of a second portion of the moving metal strip below the heat treatment temperature, wherein the second portion of the metal strip is located opposite the separation plane from the first portion.   
     
     
         10 . The method of  claim 9 , further comprising:
 cooling the first portion of the moving metal strip after heating the first portion of the moving metal strip for the duration.   
     
     
         11 . The method of  claim 9 , further comprising laterally adjusting the dimensionally variable heat treatment apparatus to move the separation plane with respect to the moving metal strip. 
     
     
         12 . The method of  claim 11 , further comprising determining a longitudinal position of the dimensionally variable heat treatment apparatus along the moving metal strip, wherein laterally adjusting the dimensionally variable heat treatment apparatus includes using the longitudinal position to move the separation plane with respect to the moving metal strip as a function of the longitudinal position. 
     
     
         13 . The method of  claim 9 , wherein the separation plane is parallel the moving metal strip, wherein heating the first portion of the moving metal strip includes heating one of a top and a bottom of the moving metal strip, and wherein cooling the moving metal strip includes removing heat from another of the top and the bottom of the moving metal strip. 
     
     
         14 . The method of  claim 9 , wherein the separation plane is parallel a longitudinal axis of the moving metal strip and perpendicular a top surface of the moving metal strip, wherein the dimensionally variable heat treatment apparatus further includes an additional heating unit and an additional cooling unit each positioned on opposite sides of the separation plane and both positioned opposite the moving metal strip from the heating unit and the cooling unit, wherein heating the first portion of the moving metal strip includes heating the top surface and a bottom surface of the moving metal strip proximate the first portion, and wherein cooling the moving metal strip includes cooling the top surface and the bottom surface of the moving metal strip proximate the second portion. 
     
     
         15 . A metal product having dimensionally variable heat treatment prepared by a method comprising:
 passing a moving metal strip through a dimensionally variable heat treatment apparatus having a heating unit and a cooling unit positioned on opposite sides of a separation plane;   heating a first portion of the moving metal strip by the heating unit, wherein heating the first portion includes raising a strip temperature of the first portion of the moving metal strip at or above a heat treatment temperature for a duration; and   cooling the moving metal strip by the cooling unit, wherein cooling the moving metal strip includes removing heat from the moving metal strip adjacent the first portion sufficiently to maintain a temperature of a second portion of the moving metal strip below the heat treatment temperature, wherein the second portion of the moving metal strip is located opposite the separation plane from the first portion.   
     
     
         16 . The product  claim 15 , wherein the method further comprises cooling the first portion of the moving metal strip after heating the first portion of the moving metal strip for the duration. 
     
     
         17 . The product of  claim 15 , wherein the method further comprises laterally adjusting the dimensionally variable heat treatment apparatus to move the separation plane with respect to the moving metal strip. 
     
     
         18 . The product of  claim 17 , wherein the method further comprises determining a longitudinal position of the dimensionally variable heat treatment apparatus along the moving metal strip, wherein laterally adjusting the dimensionally variable heat treatment apparatus includes using the longitudinal position to move the separation plane with respect to the moving metal strip as a function of the longitudinal position. 
     
     
         19 . The product of  claim 15 , wherein the separation plane is parallel the moving metal strip, wherein heating the first portion of the moving metal strip includes heating one of a top and a bottom of the moving metal strip, and wherein cooling the moving metal strip includes removing heat from another of the top and the bottom of the moving metal strip. 
     
     
         20 . The product of  claim 15 , wherein the separation plane is parallel a longitudinal axis of the moving metal strip and perpendicular a top surface of the moving metal strip, wherein the dimensionally variable heat treatment apparatus further includes an additional heating unit and an additional cooling unit each positioned on opposite sides of the separation plane and both positioned opposite the moving metal strip from the heating unit and the cooling unit, wherein heating the first portion of the moving metal strip includes heating the top surface and a bottom surface of the moving metal strip proximate the first portion, and wherein cooling the moving metal strip includes cooling the top surface and the bottom surface of the moving metal strip proximate the second portion.