Bulk nano-structured low carbon steel and method of manufacturing the same

Abstract

A method of manufacturing bulk nano-structured low carbon steel includes: preparing a blank of bulk low carbon steel; impacting the blank of bulk low carbon steel by using a compression device, so as to force the blank of bulk low carbon steel to perform a deformation at a high strain rate normally in a range of 10 2 -10 3 /s, so that the microstructure of the blank of bulk low carbon steel is nano-structured, that is, bulk nano-structured low carbon steel is thus manufactured. The bulk nano-structured low carbon steel is a plate having a thickness of not less than 5 mm or a bar having a diameter of not less than 5 mm.

1 - 12 . (canceled) 
     
     
         13 . A method of manufacturing bulk nano-structured low carbon steel, comprising:
 preparing a blank of bulk low carbon steel; and   impacting, by using a compression device, the blank of bulk low carbon steel to force the blank of bulk low carbon steel to undergo a deformation at a high strain rate in a range of 10 2 -10 3 /s, so that a microstructure of the blank of bulk low carbon steel is nano-structured to form the bulk nano-structured low carbon steel.   
     
     
         14 . The method of manufacturing bulk nano-structured low carbon steel according to  claim 13 , wherein:
 the compression device is a dynamic compression device; and   the deformation at a high strain rate is repeated multiple times.   
     
     
         15 . The method of manufacturing bulk nano-structured low carbon steel according to  claim 14 , wherein the blank of bulk low carbon steel is made of low carbon steel including approximately 0.2 wt. % of C, 0.51 wt. % of Mn, 0.73 wt. % of Si, 0.7 wt. % of Cr, and 0.14 wt. % of Cu. 
     
     
         16 . The method of manufacturing bulk nano-structured low carbon steel according to  claim 14 , wherein the strain in each deformation is set to be at least 0.1, and wherein the total accumulated strain after the deformations is set to be at least 1.4. 
     
     
         17 . The method of manufacturing bulk nano-structured low carbon steel according to  claim 14 , wherein the strain in each deformation is within a range of 0.1-0.2. 
     
     
         18 . The method of manufacturing bulk nano-structured low carbon steel according to  claim 14 , wherein the bulk nano-structured low carbon steel manufactured has one of a thickness or a diameter of not less than 5 mm. 
     
     
         19 . The method of manufacturing bulk nano-structured low carbon steel according to  claim 14 , further comprising:
 performing a heat treatment on the blank of bulk low carbon steel before the impacting step.   
     
     
         20 . The method of manufacturing bulk nano-structured low carbon steel according to  claim 14 , wherein the blank of bulk low carbon steel has one of a plate-like shape, a rectangular shape, or a cylindrical shape. 
     
     
         21 . The method of manufacturing bulk nano-structured low carbon steel according to  claim 14 , wherein a temperature in each deformation is controlled by one of a cooling system or a heating system. 
     
     
         22 . The method of manufacturing bulk nano-structured low carbon steel according to  claim 21 , wherein:
 when a cooling process is performed by using the cooling system, one of air or liquid nitrogen is selected as cooling media.   
     
     
         23 . A bulk nano-structured low carbon steel produced according to the method of  claim 14 , wherein the bulk nano-structured low carbon steel is one of a plate having a thickness of not less than 5 mm or a bar having a diameter of not less than 5 mm. 
     
     
         24 . The bulk nano-structured low carbon steel according to  claim 23 , wherein the bulk nano-structured low carbon steel has a uniform internal structure.