Press methods for coated steels and uses of steels

Abstract

Examples of methods of hot forming structural components are provided. The methods include heating a blank made from an Ultra High Strength Steel with an aluminum coating and forming the heated blank in a multi-step apparatus.

1 - 17 . (canceled) 
     
     
         18 . A method for hot forming a structural component in a multi-step apparatus, said multi-step apparatus comprising:
 a lower body,   a mobile upper body,   a mechanism configured to provide upwards and downwards press progression of the mobile upper body with respect to the lower body,   a press tool configured to draw a blank, and   a heating tool arranged upstream from the press tool,   wherein the press tool comprises:
 upper and lower mating pressing dies, each pressing die comprising one or more working surfaces that in use face the blank, and 
 the upper pressing die is connected to the mobile upper body and the lower pressing die is connected to the lower body, 
   wherein the heating tool comprises:
 upper and lower dies comprising one or more working surfaces that in use face the blank, and 
 the lower die of the heating tool is connected to the lower body and the upper die of the heating tool is connected to the mobile upper body, 
   the method comprising:
 providing a blank made of an Ultra High Strength Steel (UHSS) coated with an aluminium-silicon coating; 
 heating the blank in a furnace to a first temperature, and heating the blank from the first temperature to a second temperature in the heating tool, the second temperature being above an austenization temperature; and 
 drawing the heated blank in the press tool and transferring the blank between the press tool and the heating tool. 
   
     
     
         19 . The method according to  claim 18 , wherein the UHSS comprises in weight percentages 0.20-0.25% C; 0.75-1.5% Si and 1.50-2.50% Mn. 
     
     
         20 . The method according to  claim 19 , wherein the UHSS comprises approximately 0.22% C, 1.2% Si, 2.2% Mn. 
     
     
         21 . The method according to  claim 19 , wherein the UHSS further comprises Mn, Al, Ti, B, P, S, N. 
     
     
         22 . The method according to  claim 18 , wherein the UHSS comprises in weight percentages 0.17-0.23% C, maximum 0.5% Si, maximum 2.5% Mn, maximum 0.05% Cr, and 0.002-0.005% B. 
     
     
         23 . The method according to  claim 18 , wherein the UHSS is an air hardenable UHSS. 
     
     
         24 . The method according to  claim 18 , wherein the UHSS comprises in weight percentages 0.20-0.5% C, 0.10-0.70% Si, 0.65-1.60% Mn and 0.001-0.005% B. 
     
     
         25 . The method according to  claim 18 , wherein the multi-step apparatus further comprises a first post operation tool downstream from the press tool, the first post operation tool comprising:
 upper and lower first post operation dies comprising one or more working surfaces that in use face the blank, and   the lower first post operation die being connected to the lower body and the upper first post operation die being connected to the upper body.   
     
     
         26 . The method according to  claim 25 , wherein the first post operation tool comprises a temperature control system for controlling the temperature of the blank during the first post operation, the temperature control system optionally including thermocouples in the dies. 
     
     
         27 . The method according to  claim 25 , wherein the multi-step apparatus further comprises a second post operation tool downstream from the first post operation tool, the second post operation tool comprising:
 upper and lower second post operation dies comprising one or more working surfaces that in use face the blank, and   the lower second post operation die being connected to the lower body and the upper second post operation die being connected to the upper body.   
     
     
         28 . The method according to  claim 27 , wherein the second post operation tool comprises a temperature control system for controlling the temperature of the blank during the second post operation, the temperature control system optionally including thermocouples in the dies. 
     
     
         29 . The method according to  claim 18 , wherein the second temperature is in a range from 860° C. to 910° C. 
     
     
         30 . The method according to  claim 29 , further comprising cooling down the blank during forming. 
     
     
         31 . The method according to  claim 30 , wherein the blank is cooled down during forming to a temperature between 320° C. and 280° C. 
     
     
         32 . The method according to  claim 18 , wherein the temperature of the blank when leaving the multi-step apparatus is below 200° C. 
     
     
         33 . A method for hot forming a structural component in a multi-step apparatus, the method comprising:
 providing a blank made of an Ultra High Strength Steel (UHSS) coated with an aluminium-silicon coating;   heating the blank in a furnace to a first temperature;   heating the blank from the first temperature to a second temperature in a heating tool of the multi-step apparatus, the second temperature being above an austenization temperature;   drawing the heated blank in a press tool of the multi-step apparatus; and   transferring the blank between the press tool and the heating tool,   wherein:   the multi-step apparatus comprises a lower body, a mobile upper body, and a mechanism configured to provide upwards and downwards press progression of the mobile upper body with respect to the lower body,   the press tool comprises an upper pressing die connected to the upper body and a lower pressing die is connected to the lower body, and   the heating tool comprises an upper heating die connected to the mobile upper body, and a lower heating die connected to the lower body.   
     
     
         34 . The method according to  claim 33 , wherein the UHSS comprises in weight percentages 0.20-0.25% C; 0.75-1.5% Si and 1.50-2.50% Mn. 
     
     
         35 . The method according to  claim 34 , wherein the UHSS wherein the UHSS comprises approximately 0.22% C, 1.2% Si, 2.2% Mn. 
     
     
         36 . The method according to  claim 33 , wherein the UHSS comprises in weight percentages 0.17-0.23% C, maximum 0.5% Si, maximum 2.5% Mn, maximum 0.05% Cr, and 0.002-0.005% B. 
     
     
         37 . The method according to  claim 33 , wherein the UHSS is an air hardenable UHSS.