| US 7,491,277 B2 | ||
| Method of making cold rolled full hard steel strapping | ||
| Kenneth A. Hoffman, Deerfield, Ill. (US); Dennis A. Miller, Schaumburg, Ill. (US); and Jon E. VanHouten, Valparaiso, Ind. (US) | ||
| Assigned to Illinois Tool Works Inc., Glenview, Ill. (US) | ||
| Filed on Apr. 10, 2006, as Appl. No. 11/279,147. | ||
| Prior Publication US 2007/0235112 A1, Oct. 11, 2007 | ||
| Int. Cl. C21D 7/02 (2006.01); C21D 7/13 (2006.01) | ||
| U.S. Cl. 148—599 [148/603] | 1 Claim |
| 1. A method of making a cold rolled full hard steel strap usable in a strapping machine, the steel strap fabricated of a steel
having a tensile strength of at least about 125.7 KSI when the strap has a width of about 0.500 inches and a thickness of
0.020 inches, consisting of the steps of:
forming a steel consisting essentially of: 0.02 to 0.25 percent carbon, 0.15 to 1.50 percent manganese, 0.01 to 0.12 percent
aluminum, 0.03 to 0.04 percent nitrogen, 0.04 to 0.50 percent copper, 0.03 to 0.25 percent nickel, 0.02 to 0.25 percent molybdenum,
0.03 to 0.25 percent chromium, maximum 0.05 percent phosphorous, maximum 0.05 percent sulfur, and maximum 0.25 percent silicon,
and a balance of iron;
hot rolling the steel into a continuous sheet of hot band steel at a temperature above the Ac3 temperature and at a finishing temperature in the range of approximately 1350° F. to 1400° F.;
coiling the steel at a coiling temperature of approximately 1150° F.;
allowing the coiled steel to air cool;
reducing the coiled steel at least approximately 50 percent by cold rolling to increase tensile strength;
recoiling the cold rolled sheet without heat treating the sheet; and
fabricating the cold rolled sheet into steel straps without heat treating the straps.
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