Ultra-high strength weathering steel piles and structural foundations

Abstract

Disclosed herein is a light-gauge, ultra-high strength weathering steel pile for use as a steel foundation in structures such as, for example, solar arrangements. The light-gauge, ultra-high strength weathering steel pile comprises a thickness of 2.5 mm or less that has been cold roll formed into a steel pile having a plurality of sidewalls. The steel pile further comprises a yield strength of between 700 and 1600 MPa, a tensile strength of between 1000 and 2100 MPa, and an elongation of between 1% and 10%.

What is claimed is: 
     
         1 . An ultra-high strength weathering steel pile comprising:
 a plurality of sidewalls, each having a thickness of about 2.5 mm or less and a composition comprising, by weight,
 (i) between 0.20% and 0.35% carbon, less than 1.0% chromium, between 0.7% and 2.0% manganese, between 0.10% and 0.50% silicon, between 0.1% and 1.0% copper, less than or equal to 0.12% niobium, less than 0.5% molybdenum, between 0.5% and 1.5% nickel, and silicon killed containing less than 0.01% aluminum, and 
 (ii) the remainder iron and impurities resulting from melting; 
   the pile having a corrosion index of 6.0 or greater, a yield strength of between 700 and 1600 MPa, a tensile strength of between 1000 and 2100 MPa, and an elongation of between 1% and 10%.   
     
     
         2 . The ultra-high strength weathering steel pile of  claim 1  wherein the thickness is about 2.0 mm or less. 
     
     
         3 . The ultra-high strength weathering steel pile of  claim 1  wherein the thickness is about 1.6 mm or less. 
     
     
         4 . The ultra-high strength weathering steel pile of  claim 1  cold formed from a steel strip where the thickness is a hot rolled thickness that is between a 15% and 50% reduction of the thickness. 
     
     
         5 . The ultra-high strength weathering steel pile of  claim 4  wherein the hot rolled thickness is a high friction rolled thickness. 
     
     
         6 . The ultra-high strength weathering steel pile of  claim 1  that is a hemmed C-channel wherein the plurality of sidewalls are a web and one or more flanges. 
     
     
         7 . The ultra-high strength weathering steel pile of  claim 1  that is a corrugated C-channel wherein the plurality of sidewalls are a web and one or more flanges. 
     
     
         8 . The ultra-high strength weathering steel pile of  claim 1  that is a corrugated tube. 
     
     
         9 . The ultra-high strength weathering steel pile of  claim 8  wherein the corrugated tube is generally square. 
     
     
         10 . The ultra-high strength weathering steel pile of  claim 8  wherein the corrugated tube is generally rectangular. 
     
     
         11 . The ultra-high strength weathering steel pile of  claim 1  wherein the plurality of sidewalls do not have a separately applied coating. 
     
     
         12 . The ultra-high strength weathering steel pile of  claim 1  wherein the plurality of sidewalls are ungalvanized. 
     
     
         13 . The ultra-high strength weathering steel pile of  claim 1  wherein at least one sidewall of the plurality of sidewalls comprises one or more corrugations. 
     
     
         14 . The ultra-high strength weathering steel pile of  claim 1  wherein each sidewall of the plurality of sidewalls comprise one or more corrugations. 
     
     
         15 . A solar arrangement comprising:
 an ultra-high strength weathering steel pile comprising:   a plurality of sidewalls, each having a thickness of about 2.5 mm or less and a composition comprising:   (i) by weight, between 0.20% and 0.35% carbon, less than 1.0% chromium, between 0.7% and 2.0% manganese, between 0.10% and 0.50% silicon, between 0.1% and 1.0% copper, less than or equal to 0.12% niobium, less than 0.5% molybdenum, between 0.5% and 1.5% nickel, and silicon killed containing less than 0.01% aluminum, and   (ii) the remainder iron and impurities resulting from melting;   the ultra-high strength weathering steel pile having a corrosion index of 6.0 or greater, a yield strength of between 700 and 1600 MPa, a tensile strength of between 1000 and 2100 MPa, and a elongation of between 1% and 10%; and   wherein a partial length of the ultra-high strength weathering steel pile is driven into a ground surface and one or more solar cells are supported above the ground surface by the ultra-high strength weathering steel pile.   
     
     
         16 . The solar arrangement of  claim 15  wherein the plurality of sidewalls are a web and one or more flanges and form a hemmed C-channel. 
     
     
         17 . The solar arrangement of  claim 15  wherein the plurality of sidewalls are a web and one or more flanges and form a corrugated C-channel. 
     
     
         18 . The solar arrangement of  claim 15  wherein the plurality of sidewalls form a corrugated tube. 
     
     
         19 . An ultra-high strength weathering steel pile comprising:
 a plurality of sidewalls, each having a thickness of about 2.5 mm or less, a corrosion index of 6.0 or greater, a yield strength of between 700 and 1600 MPa, a tensile strength of between 1000 and 2100 MPa, and a elongation of between 1% and 10%.   
     
     
         20 . The ultra-high strength weathering steel pile of  claim 19  having a composition comprising:
 (i) by weight, between 0.20% and 0.35% carbon, less than 1.0% chromium, between 0.7% and 2.0% manganese, between 0.10% and 0.50% silicon, between 0.1% and 1.0% copper, less than or equal to 0.12% niobium, less than 0.5% molybdenum, silicon killed containing less than 0.01% aluminum, and an amount of nickel sufficient for shifting a peritectic point away from the carbon region and/or increasing a transition temperature of the peritectic point to form a carbon alloy steel strip having a microstructure of at least 75% by volume martensite or martensite plus bainite, and 
 (ii) the remainder iron and impurities resulting from melting.