超低淬透性、超高碳齿轮钢代替渗碳淬火工艺是否可行？
An ultrahigh carbon steel alloy containing 1.4 wt pct carbon (UHCS-1.4C) was studied. The steel was processed into ultrafine grain and fully spheroidized microstructure through a controlled rolling and controlled-cooling divorced eutectoid transformation, and was then given austempering treatment to form bainite. The mechanical properties of the heat-treated steel were evaluated by tension tests at room temperature. After austenitized at 850 °C and then austempered at 300 - 350 °C, the microstructure was ultrafine upper bainite, retained austenite, and unsolvable cementite. It was shown that the ultimate tensile strengths of UHCS-1.4C ranged from 1420 to 1830 MPa, elongations to failure from 6 to 14%; the ultimate tensile strength increases with decreasing austempering temperature, while the tensile ductility decreases. The fracture surface of bainitic UHCS-1.4C consists mainly of dimples and voids, which reveal a ductile fracture. The present results indicate that ultrahigh carbon steel can be easily processed to achieve bainitic microstructures and unique properties.一个超高碳钢合金含有1.4 wt pct碳(uhcs - 1.4 c)进行了研究。钢晶粒超细化加工成,完全球化处理组织通过控制轧制和controlled-cooling离异共析转变,和当时贝氏体等温淬火处理形式。热处理钢的机械性能被张力测试在室温下进行。在850°C,然后austempered austenitized后300 - 350°C,超细上贝氏体组织,残留奥氏体,解决渗碳体。 结果表明,极限抗拉强度的uhcs - 1.4 c范围从1420到1830 MPa,elongations失败从6 - 14%;极限抗拉强度的增加而减少等温淬火温度,而拉伸延性下降。贝氏体的断裂表面uhcs - 1.4 c主要由酒窝和空洞,这显示出韧性断裂。目前的结果表明,超高碳钢可以很容易地处理获得贝氏体显微结构和独特的性质。
超高碳钢与渗碳钢力学性能
材料奥氏体化温度/℃正火屈服点ss/MPa抗拉强度sb/MPa屈强比(ss/sb)延伸率d/%面缩率y/%断裂强度sf/MPa
UHCS-1.4C780 6249340.6722361256
UHCS-1.4C82090213070.6913311700
UHCS-1.4C86095314390.6612261748
UHCS-1.3C86090313270.6812311702
20CrMnTi880淬火/200回火83510801045
20CrMnMo850淬火/200回火88511751045
有人提出采用低淬透性超高碳钢感应淬火的工艺代替传统的低碳合金钢渗碳淬火工艺加工齿轮。
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