超深钻探井底动力机具磨损失效及复合金刚石薄膜改性

发布时间：2018-02-28 12:22

本文关键词： 地质钻探井底动力机具磨损失效复合金刚石薄膜改性机理　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：从改善超深钻探井底动力机具活动部件的耐磨损性能出发,采用复合表面改性技术对易磨损活动部件表面进行改性,中频磁控溅射SiC过渡层,和热丝化学气相沉积金刚石薄膜;探讨了主要制备工艺参数对薄膜成分结构及其表面光洁度的影响,获得晶面取向均一、金刚石相含量高和表面光洁度高的性能,并通过摩擦磨损实验验证了复合金刚石薄膜在旋转部件和往复部件表面沉积后的改性效果,构建了复合金刚石薄膜的改性机理,为制备具备良好耐磨性能的井底动力机具部件提供理论依据与实验基础。主要结论有:(1)通过热丝化学气相沉积系统在优质合金钢38CrMoAl基材上制备含SiC过渡层的复合金刚石薄膜。随着氩气体积、甲烷氢气比和功率增大,金刚石薄膜呈现(111)晶向择优生长,并伴随少量的(220)晶向晶粒。薄膜中sp3相含量先升高后降低,分别在30 vol.%Ar、1.0 vol.%CH4/H2和功率为7 KW时达到最大值。表征表面光洁度的表面粗糙度和粒径呈现出先增大后减小的趋势,分别在30 vol.%Ar、1.5 vol.%CH4/H2和功率5 KW时表面光洁度最优。(2)利用MS-T3000磨损试验机分析螺杆马达转子样品镀膜前后摩擦学性能。在钻井液中的螺杆马达转子发生以腐蚀磨损为主。随着载荷由,薄膜的摩擦系数和磨损率均随着载荷增大(由1 N增大到7 N)而增大,磨损加剧;摩擦热导致薄膜中的金刚石相向石墨相转化。改性机理为:摩擦副接触面平整化,摩擦热导致接触面石墨化起固体润滑,和金刚石碎片和石墨嵌入薄膜表面使得薄膜具备低的摩擦系数和高的耐磨性,高结合力的过渡层使得金刚石薄膜具备不易脱落的特性。(3)在利用CSM往复磨损试验机分析钻井冲击器活塞镀膜前后摩擦学性能。在钻井液中钻井冲击器活塞失效机理为磨粒磨损。随着往复频率增大,薄膜的摩擦系数和磨损率均随之增大(摩擦系数0.04~0.08,磨损率15~32×10-7mm3/N·mm),表面磨痕深度增加。薄膜中的石墨相增多,金刚石相减少。机理为:摩擦副接触后,接触面平整化;钻井液削弱机械锁合效应,起边界润滑作用;形成转移膜进一步减小摩擦系数。
[Abstract]:In order to improve the wear resistance of the moving parts of ultra-deep drilled bottom power machine, the surface of wear-prone moving parts was modified by composite surface modification technology. The intermediate frequency magnetron sputtering SiC transition layer and hot filament chemical vapor deposition diamond films were used. The effects of main preparation parameters on the composition structure and surface finish of the films were discussed. The properties of uniform orientation of crystal plane, high content of diamond phase and high surface finish were obtained. The modified effect of the composite diamond film on the surface of the rotating and reciprocating parts was verified by friction and wear experiments. The modification mechanism of the composite diamond film was constructed. In order to provide theoretical basis and experimental basis for the preparation of bottom-hole power tool parts with good wear resistance, the main conclusions are as follows: (1) the composite containing SiC transition layer was prepared on high quality alloy steel 38CrMoAl substrate by hot-filament chemical vapor deposition system. Diamond films. With the volume of argon, With the increase of CH4 / H _ 2 ratio and power, the diamond film exhibits preferential growth in the crystal direction of 111), accompanied by a small amount of crystal grains in the direction of Ni _ (220). The content of sp3 phase in the film increases at first and then decreases. The maximum values of surface roughness and particle size were obtained at 30 vol.Aran 1.0 vol.%CH4/H2 and 7 KW power, respectively. The surface roughness and particle size of surface finish showed a tendency of first increasing and then decreasing. Using MS-T3000 wear tester to analyze the tribological properties of screw motor rotor sample before and after coating. The corrosion wear of screw motor rotor is dominant in drilling fluid. The friction coefficient and wear rate of the film increase with the increase of load (from 1 N to 7 N), and the friction heat results in the transformation of diamond phase to graphite phase in the film. Friction heat results in graphitization of the contact surface and solid lubrication, and diamond fragments and graphite embedded on the surface of the film make the film have low friction coefficient and high wear resistance. The transition layer with high adhesion makes diamond film easy to fall off. (3) the tribological properties of drilling percussion piston before and after coating are analyzed by using CSM reciprocating wear tester. Drilling impactor piston invalidation machine in drilling fluid. Abrasive wear. As the reciprocating frequency increases, The friction coefficient and wear rate of the film increased (friction coefficient 0.04 ~ 0.08, wear rate 1532 脳 10 ~ (-7) mm ~ (3) N 路mm ~ (-1)), wear depth increased, graphite phase increased and diamond phase decreased. The drilling fluid weakens the mechanical locking effect and plays the role of boundary lubrication, and the formation of transfer film further reduces the friction coefficient.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P634.4;TG174.4

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