抽油机球铁齿轮的化学成分及生产工艺

Chemical constitution and manufacturing process for ductile iron gear on pumping units

为提高抽油机减速器齿轮铸件的机械性能，提出以Sn代替Mo作为合金元素，并通过试验确定了合理的Si、Cu、Sn的加入量。指出Si加入量应控制在1．9％－2．1％范围内，同时加入0．36％～0．9％的Cu和0．025％～0．07％的Sn，可保证球铁的强度和延伸率都满足QT700－2的要求。鉴于试件与实际铸件的表面硬度有一定的差值，为提高铸件表面硬度，进行了余热正火试验，并给出了铸件在铸型内的时间－冷却温度曲线。最后根据球铁化学成分的选择结果，进行了齿轮生产试验。

To improve the mechanical properties of cast gear of pumping unit reducer, it is proposed using Sn as alloy element instead of Mo, and rational contains of Si 9 Cu and Sn are determined by means of test. It is indicated that the contain of Si should be controlled between 1.9% and 2. 1%, and by adding 0.36% ~ 0.9% Cu and 0.025% ~ 0.07% Sn, the strength and coefficient of elongation of the ductile iron can satisfy the requirements of Q1/00-2. In view of the differential value of the surface hardness of the test piece and the casting, to improve the surface hardness of the casting, waste heat normalizing test is carried out, and the time-temperature curve of the casting in mould is given. According to the selection result of the chehacal constitution of ductile iron, trial manufacture of the gear is carried out.