Metal treatment – Process of modifying or maintaining internal physical... – Heating or cooling of solid metal
Reexamination Certificate
2007-10-30
2007-10-30
Kastler, Scott (Department: 1742)
Metal treatment
Process of modifying or maintaining internal physical...
Heating or cooling of solid metal
C148S320000, C148S581000
Reexamination Certificate
active
10120471
ABSTRACT:
An improved steel railroad rail, and methods for producing same, having a high-carbon content in a range from more than 0.9 to 1.1 wt % is provided that has increased wear resistance and increased fracture toughness over conventional steel rail. The high-carbon rail is characterized as having a pearlitic phase of an eutectoid nature. The average ultimate tensile strength is in a range from 204,860 to 222,120 psi, with a minimum of 174,000 psi. The average yield strength is in a range from 132,320 to 148,450 psi, with the minimum of 120,000 psi. The average percent elongation is in a range from 10.50 to 11.14, with a minimum of 10.00. The Brinell hardness on the surface at any position of the head top and upper gage corners of the rail is in a range from 390 to 440 BHN. The hardness 19 mm below the top surface is in a range from 360 to 435 BHN and 19 mm below the surface at the upper gage corners is in a range from 360 to 410 BHN. The characteristics of the steel rail produced in accordance with the present invention is a substantial improvement as compared with rail used today. The production of a fully pearlitic steel rail having a carbon content from more than 0.9 to 1.1 wt % is remarkable and unexpected. A steel rail of this type having a hardness in a range from 400 to 440 BHN and a combination of yield strength, ultimate tensile strength, elongation and surface and in-depth Brinell hardness goes beyond all expectations and results in a superior and commercially important steal rail.
REFERENCES:
patent: 4913747 (1990-04-01), Fukuda et al.
patent: 5658400 (1997-08-01), Uchino et al.
patent: 5759299 (1998-06-01), Yokoyama et al.
patent: 5762723 (1998-06-01), Ueda et al.
patent: 5830286 (1998-11-01), Veda et al.
patent: 401159327 (1989-06-01), None
patent: 2000-178690 (2000-06-01), None
patent: 2001-3140 (2001-01-01), None
English translation of Japanese patent 1-159327, Hideaki Kageyama, et al, Jun. 22, 1989.
CF&I Steel, L.P.
Kastler Scott
Schwabe Williamson & Wyatt
LandOfFree
High impact and wear resistant steel does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High impact and wear resistant steel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High impact and wear resistant steel will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3844491