Ultra-high strength rebar

Abstract

A high mechanical strength reinforcement, hot rolled steel, in particular, rebar suitable for construction in areas prone to seismic activity, comprising iron, at most 0.4 weight percent carbon, at most about 0.4 weight percent vanadium and/or niobium, at most about 1.6 weight percent of manganese, at most about 0.5 weight percent of silicon, and the usual residual elements of scrap steel. A method of reinforcing a dwelling from damage resulting from seismic activity, the method comprising providing, as a component of the dwelling, at least one high strength, hot rolled steel rebar with high mechanical strength which meets the requirements of construction, in particular, rebar suitable for construction in areas prone to seismic activity, comprising iron, at most 0.4 weight percent carbon, at most about 0.4 weight percent vanadium and/or niobium, at most about 1.6 weight percent of manganese, at most about 0.5 weight percent of silicon, and the usual residual elements of scrap steel.

1 . A reinforcement steel consisting essentially of, in addition to iron:
 carbon: between 0.2 and 0.4 weight percent;   manganese: between 1.0 and 1.6 weight percent;   silicon: between 0.1 and 0.5 weight percent;   copper: between 0.1 and 0.5 weight percent;   vanadium: between 0.1 and 0.4 weight percent;   chromium: between 0.01 and 0.5 weight percent;   nickel: between 0.01 and 0.5 weight percent;   molybdenum: trace to 0.1 weight percent;   niobium: trace to 0.1 weight percent;   phosphor: trace to 0.1 weight percent;   sulfur: trace to 0.1 weight percent;   
       wherein:
 when vanadium is present at 0.1 to less than 0.3 weight percent, -no intentionally added niobium is present; 
 when vanadium is present at 0.3 to at most about 0.35 weight percent, less than 0.05 weight percent intentionally added niobium is present; and 
 the usual residual elements of scrap steel. 
 
     
     
         2 . A reinforcement steel of  claim 1 , wherein:
 carbon is present at most 0.3 weight percent; and   manganese is present at most 1.5 weight percent;   the steel having a carbon equivalent of at most 0.55 weight percent calculated as per ASTM A706/A706M-09b.   
     
     
         3 . A reinforcement steel of  claim 1 , wherein:
 manganese is present at more than 1.0 to at most about 1.5 weight percent; and   copper is present at more than 0.25 to at most about 0.4.   
     
     
         4 . A reinforcing bar having the composition of  claim 1 , wherein the rod is of a size between size #3 rebar to size #18 rebar with a yield strength of at least 90 ksi to about 105 ksi and a tensile strength of at least 112 ksi to 133 ksi. 
     
     
         5 . A reinforcing bar having the composition of  claim 2 , wherein the rod is of a size between size #3 rebar to size #18 rebar with a yield strength of at least 90 ksi to about 105 ksi and a tensile strength of at least 112 ksi to 133 ksi. 
     
     
         6 . A reinforcing bar having the composition of  claim 3 , wherein the rod is of a size between size #3 rebar to size #18 rebar with a yield strength of at least 90 ksi to about 105 ksi and a tensile strength of at least 112 ksi to 133 ksi. 
     
     
         7 . A concrete form comprising at least one rebar having a composition defined by  claim 1 . 
     
     
         8 . A concrete form comprising at least one rebar having a composition defined by  claim 2 . 
     
     
         9 . A concrete form comprising at least one rebar having a composition defined by  claim 3 . 
     
     
         10 . A method of reinforcing a dwelling from damage resulting from seismic activity, the method comprising;
 providing, as a component of the dwelling, at least one rebar of a composition consisting essentially of, in addition to iron:   carbon: between 0.2 and 0.4 weight percent;   manganese: between 1.0 and 1.6 weight percent;   silicon: between 0.1 and 0.5 weight percent;   copper: between 0.1 and 0.5 weight percent;   vanadium: between 0.1 and 0.4 weight percent;   chromium: between 0.01 and 0.5 weight percent;   nickel: between 0.01 and 0.5 weight percent;   molybdenum: trace to 0.1 weight percent;   niobium: trace to 0.1 weight percent;   phosphor: trace to 0.1 weight percent;   sulfur: trace to 0.1 weight percent; and   when vanadium is present at 0.1 to less than 0.3 weight percent, -no intentionally added niobium is present; and   when vanadium is present at 0.3 to at most about 0.35 weight percent, less than 0.05 weight percent intentionally added niobium is present; and   the usual residual elements of scrap steel.   
     
     
         11 . The method of  claim 10 , wherein, in the rebar:
 carbon is present at most 0.3 weight percent; and   manganese is present at most about 1.5 weight percent;   the rebar having a carbon equivalent of at most 0.55 weight percent calculated as per ASTM A706/A706M-09b.   
     
     
         12 . The method of  claim 10 , wherein, in the rebar:
 manganese is present at more than 1.0 to at most 1.5 weight percent; and   copper is present at more than 0.25 to at most about 0.4.   
     
     
         13 . The method of  claim 10 , wherein the component of the dwelling comprises a concrete construction element comprising the at least one rebar. 
     
     
         14 . The method of  claim 13 , wherein the rebar is of size of one of size #3 rebar to size #18 rebar, with a yield strength of at least 90 ksi to about 105 ksi and a tensile strength of at least 112 ksi to 133 ksi. 
     
     
         15 . The method of  claim 10 , wherein the rebar is hot rolled into a desired diameter and then air cooled without further heat treatment.