Steel and coupler made from the same

Abstract

The present invention provides a type of steel and a coupler made from same, comprising the following compositions in percentages by weight: carbon: 0.24-0.32%, silicon: 0.20-0.50%, manganese: 1.30-1.70%, phosphorus: less than or equal to 0.02%, sulphur: less than or equal to 0.02%, copper: less than or equal to 0.30%, chromium: 0.50-0.80%, nickel: 0.40-0.70%, molybdenum: 0.25-0.45%, aluminium: 0.02-0.08%, and the remainders are iron and other inevitable elements. The steel of the present invention is advantaged in high strength and excellent toughness and therefore the mechanical property thereof is better than the standard of conventional grade E steel.

1 . A steel, characterized by comprising the following compositions in percentages by weight: carbon: 0.24-0.32%, silicon: 0.20-0.50%, manganese: 1.30-1.70%, phosphorus: less than or equal to 0.02%, sulphur: less than or equal to 0.02%, copper: less than or equal to 0.30%, chromium: 0.50-0.80%, nickel: 0.40-0.70%, molybdenum: 0.25-0.45%, aluminium: 0.02-0.08%, and the remainders are iron and other inevitable elements. 
     
     
         2 . The steel in  claim 1 , characterized in that: the percentage of the carbon by weight is 0.25-0.29%. 
     
     
         3 . The steel in  claim 2 , characterized in that: the percentage of the carbon by weight is 0.25-0.28%. 
     
     
         4 . The steel in  claim 1 , characterized in that: the percentage of the manganese by weight is 1.35-1.60%. 
     
     
         5 . The steel in  claim 4 , characterized in that: the percentage of the manganese by weight is 1.35-1.55%. 
     
     
         6 . The steel in  claim 1 , characterized in that: the percentage of the phosphorus by weight is less than or equal to 0.015%. 
     
     
         7 . The steel in  claim 1 , characterized in that: the percentage of the sulphur by weight is less than or equal to 0.015%. 
     
     
         8 . The steel in  claim 1 , characterized in that: the percentage of the aluminium by weight is 0.02-0.06%. 
     
     
         9 . The steel in  claim 8 , characterized in that: the percentage of the aluminium by weight is 0.02-0.05%. 
     
     
         10 . A coupler made of the steel in the  claim 1 . 
     
     
         11 . A coupler made of the steel in the  claim 2 . 
     
     
         12 . A coupler made of the steel in the  claim 3 . 
     
     
         13 . A coupler made of the steel in the  claim 4 . 
     
     
         14 . A coupler made of the steel in the  claim 5 . 
     
     
         15 . A coupler made of the steel in the  claim 6 . 
     
     
         16 . A coupler made of the steel in the  claim 7 . 
     
     
         17 . A coupler made of the steel in the  claim 8 . 
     
     
         18 . A coupler made of the steel in the  claim 9 .