| 摘要 |
<p>1,186,149. Heat-treating steel wheels. AMSTED INDUSTRIES Inc. Sept. 30, 1968 [Oct.18, 1967], No.46323/68. Headings C7A and C7N. A railway wheel cast from steel containing in percentage by weight:- C 0À4 to 0À85 Mn 0À5 to 0À9 Si 0À25 to 0À5 P, S not more than 0À05 each Fe balance is cooled to a temperature within the range 1250‹F. to room temperature, heated to the normalizing temperature e.g. about 1700‹ F. and is then cooled until the entire wheel has reached 1200‹ F. or e. g. 1150‹ -1200<SP>‹</SP> F., the ends of the hub section being covered with insulating material while the remainder of the wheel is allowed to cool in the atmosphere. The insulating material may be in the form of caps covering the ends of the hub section; alternatively cooling may take place while the wheels are on a conveyer over which there is located a strip of material spaced slightly above the upper end of the hub section. Additionally in this latter method a heating element, induction coil or gas flame may be incorporated in the cover strip to retard cooling of the hub.</p> |
