| 摘要 |
<p>A low alloy steel composition having a medium carbon content which is capable of use as a forging die in closed die forging and in which surface problems, such as panel cracking, in the manufacturing process have been eliminated, or the frequency thereof very greatly reduced as contrasted with conventional steels. The invention provides such a steel in which the reduction of area transverse is in the range of from about 15% to about 30%, and in which the ratio of reduction of area transverse to the reduction of area longitudinal closely approaches 1.0. The steel has from about .50 to about .60 percent by weight of carbon and significant nickel, chromium, molybdenum, vanadium and aluminum constituents, and a small but effective quantity of titanium. The method of producing such steel includes the feature of adding titanium to the molten steel at a point in the processing cycle in which oxygen content of the molten steel is at a low point whereby relatively harmless titanium carbo nitride is produced instead of aluminum nitride which is recognized as being deleterious to the attainment of the above-described properties.</p> |
