摘要:自升式海洋钻井平台是海洋油气开发的重要装备，液压活塞杆是钻井平台的关键零件之一。海洋环境条件十分苛刻，具有强烈的腐蚀能力，难以保证液压活塞杆长期稳定的运行。在这种苛刻环境条件下，单靠提高活塞杆材料自身的性能很难能满足其在这种苛刻环境下稳定运行。本文采用大气等离子喷涂工艺，在2Cr13马氏体不锈钢表面制备NiCrBSi重熔涂层（约150μm）+喷涂涂层（约350μm）的复合结构涂层。其中重熔涂层通过热处理炉进行重熔处理，重熔温度分别为950℃、1000℃、1050℃以及1100℃，时间为1h。

利用扫描电子显微镜(SEM)、光谱仪(EDS)和X射线衍射仪(XRD)等方法分析重熔前后涂层的孔隙率、微观组织结构、物相变化，通过拉伸、显微硬度和摩擦磨损试验研究了涂层的结合强度、显微硬度分布和摩擦磨损性能，并研究涂层在3.5%NaCl水溶液中的耐腐蚀性能。

经重熔处理后，涂层的致密度明显提高，硬度及结合强度也有所增加。经过重熔处理后，涂层的结合强度明显增大，重熔涂层与基体结合的更加牢固；随着重熔温度提高，摩擦系数逐步提高，重熔涂层的磨损量明显小于未重熔的喷涂涂层，耐磨损性能增加；重熔涂层的腐蚀电位高于喷涂涂层的腐蚀电位，耐蚀性也优于喷涂涂层。

关键词：等离子喷涂；NiCrBSi；重熔处理；涂层性能

Abstract:The jack- up offshore drilling platform is an important equipment for deep-sea oil and gas development. Hydraulic piston rods are one of the key parts of the drilling platform. The marine environment is very harsh, with a strong corrosive ability, it  is  difficult  to ensure long-term stable operation of the hydraulic piston rod. It is difficult to improve the properties of the base material itself by itself in such a harsh environment. In this paper, NiCrBSi remelting coating (about 150μm) and spray coating composite coating (about 350μm) was prepared on the surface of 2Cr13 martensitic stainless steel by atmospheric plasma  spraying process.  The  remelting coating was remelted  by  heat treatment furnace.

The  remelting  temperatures  were 950  ℃, 1000  ℃, 1050  ℃ and 1100  ℃,  respectively.The microstructures, phase changes, interfacial bonding and were analyzed by scanning electron microscopy (SEM), spectroscopy (EDS) and X-ray diffraction (XRD). Tensile strength, microhardness and friction wear properties of the coating were studied. The  corrosion  resistance  of the coating  in  3.5% NaCl aqueous  solution  was studied.

After the remelting treatment, the density of the coating is obviously improved, the microhardness and the bonding strength are also increased. the bonding strength of the coating is obviously increased, and the remelting coating is more firmly bonded with the substrate. With the increase of the remelting temperature, the friction coefficient is gradually increased, the wear amount of the remelted coating is obviously smaller than that of the sprayed coating. The corrosion potential of the remelting coating is higher than  that of the  sprayed  coating,  and the corrosion  resistance  is  better than  that  of sprayed coating.

Keywords:  plasma  spraying;   NiCrBSi;  remelting  treatment;   coating performance

目录

第一章 绪论 1

1.1选题背景及意义 1

1.2自升式钻井平台 2

1.2.1自升式钻井平台介绍 2

1.2.2升降系统