Effects of Alloying Additions on the Liquid and Solid State Processing Characteristics of Machinable SAE 4120 Steel Grades

该奖项是两个工业/大学合作研究中心（I/UCRC）之间的“Tie”项目，旨在评估合金添加剂对SAE 4120合金钢的液体和固体加工特性的影响，添加合金以提高钢的可加工性。科罗拉多矿业学院的先进钢铁加工和产品工业/大学合作研究中心正在确定合金化和溶质偏析对合金热加工行为和最终显微组织的影响。卡耐基梅隆大学的钢铁研究工业/大学合作研究中心正在评估这些合金添加对渣-金属相互作用和凝固特性的影响。这两项努力定义了选定合金添加的独立但合作的研究，并且联合研究在可加工钢的理解中创造了协同作用，这在任何一个机构单独都是不可能的。环境和健康问题增加了取代铅作为提高钢材可加工性的添加剂的紧迫性。许多化学元素都有可能替代铅，例如铜、铌、铋、碲和硒。已知这些元素中的一些会对热短性（描述钢在合理加工温度下的变形能力）、脆性、钢中合金元素的偏析、凝固和铸造过程以及钢在熔炼炉中与耐火衬里的反应产生不利影响。使用这些合金元素作为有毒铅的替代品时，必须避免上述任何不利情况。科罗拉多矿业学院正在研究这种钢的性能，卡耐基梅隆大学正在研究同一种实验合金的熔化、铸造和凝固特性。这种专业知识的结合解决了这些新合金在商业上可行之前所需的全部问题。项目经理建议科罗拉多矿业学院为这一“Tie”项目获得为期36个月的75,000美元奖励。

9417437 Matlock This award is a "Tie" project between two Industry/University Cooperative Research Centers (I/UCRC) designed to evaluate the effects of alloy additions, added to enhance machinability of the steel, on the liquid and solid state processing characteristics of SAE 4120 alloy steel. The Industry/University Cooperative Research Center for Advanced Steel Processing and Products at Colorado School of Mines is determining the effects of alloying and solute segregation on the hot working behavior and final microstructures of the alloys. The Industry/University Cooperative Research Center for Iron and Steel Research at Carnegie Mellon University is evaluating the effects of these alloying additions in slag-metal interactions and solidification characteristics. The two efforts define independent yet collaborative studies of selected alloy additions, and the combined research creates a synergism in the understanding of machinable steels that would not be possible at either institution alone. Environmental and health concerns increase the urgency of replacing lead as an additive for enhanced machinability of steels. A number of chemical elements have potential substitutes for the lead, for example copper, niobium, bismuth, tellurium, and selenium. Some of these elements are known to adversely affect the hot shortness (a term that describes the deformability of the steel over a reasonable processing temperature), brittleness, segregation of alloying elements in the steel, solidification and casting processes, and the reaction of the steel melt with the refractory lining in the smelting furnace. Any utilization of these alloying elements as substitutes for toxic lead must be done in a manner to avoid any of the adverse situations above. Colorado School of Mines is investigating the properties of the steel and Carnegie Mellon University is investigating the melting, casting and solidification characteristics of the same experimental alloys. This c ombination of expertise addresses the complete scope of issues needed before these new alloys can become commercially viable. The Program Manager recommends Colorado School of Mines be awarded $75,000 for 36 months for this "Tie" project.