High performance steel strapping for elevated temperature service and method thereof
AssigneesUSX Corporation, Illinois Tool Works Inc.
InventorsGregory A. Dries, Philip M. Roberts
Life of this patent
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Abstract
Improved steel strapping and method for producing comprising adding to a steel composition of about 0.25 to about 0.34 wt. % carbon, about 1.20 to about 1.55 wt. % manganese and up to about 0.035 wt. % silicon, an addition consisting of about 0.20 to about 0.25 wt. % vanadium, or 0.35 to about 0.45 wt. % molybdenum, or about 0.35 to about 0.45 wt. % molybdenum plus about 0.12 to about 0.18 wt. % vanadium, casting, hot rolling and cold rolling the steel to strapping form and austempering the steel strapping.
Claims6
A method for producing steel strapping of enhanced tensile strength on prolonged exposure to elevated temperatures comprising providing a steel composition consisting essentially of, by weight percent, about 0.25% to about 0.34% carbon, about 1.20% to about 1.55% manganese, and up to about 0.035% silicon, modifying said steel by an addition selected from the group consisting of from about 0.20% to about 0.25% vanadium, from about 0.35% to about 0.45% molybdenum, and from about 0.35% to about 0.45% molybdenum plus from about 0.12% to about 0.18% vanadium, casting the steel, hot rolling the steel to strip form, cold rolling the steel strip to strapping gage, slitting the cold-rolled steel strip to strapping width, and austempering the steel before or after slitting to strapping width.
Steel strapping produced from a steel composition consisting essentially of, by weight percent, 0.25% to 0.34% carbon, 1.2% to 1.55% manganese, 0.035% maximum silicon, and a high temperature strengthening component selected from the group consisting of from about 0.20% to about 0.25% vanadium, from about 0.35% to about 0.45% molybdenum, and from about 0.35% to about 0.45% molybdenum plus from about 0.12% to about 0.18% vanadium, wherein the steel has been hot rolled, cold rolled to strapping gage, slit to strapping width, and, before or after slitting, has been austempered, providing a non-equilibrium microstructure of fine spheroidized carbides in ferrite, said strapping having enhanced retention of tensile strength after prolonged exposure to elevated temperatures as compared to the steel free of said strengthening component.
Dependencies are inferred from the claim text.