| 摘要 |
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.
|
