中文摘要：

为提高油气钻采设备的耐腐蚀性能,采用热丝TIG焊工艺在直径为35 mm、深度为254 mm的AISI8630小孔内壁堆焊Inconel625合金。以堆焊稀释率为指标,运用正交试验法优化堆焊参数。应用OM、EDS及SEM等对堆焊层的显微组织及元素分布进行分析,采用失重法测定堆焊层及母材的腐蚀速率。结果表明：采用优化后的堆焊参数可在AISI8630小孔内壁获得性能良好、无缺陷的堆焊层;堆焊层主要由柱状奥氏体、枝晶和枝晶间共晶组成,熔合线处为平面晶组织,热影响区主要由柱状晶和等轴枝晶组成;从基体到堆焊层合金元素含量迅速增加,堆焊层中合金元素的含量较均匀。Inconel625合金具有较强的耐腐蚀性能,腐蚀速率约为AISI8630的1/6~1/5,堆焊后的小孔工件耐腐蚀性能得到大幅提升。

英文摘要：

In order to improve the corrosion resistance of the petroleum and natural gas drill equipments, the Incone1625 alloy was claded on the surface of AISI8630 small hole with diameter of 35 mm and depth of 254 mm by using bot-wire TIG welding. Taking the dilution ratio of cladding layer as the target, the orthogonal experiment method was adopted to optimize the cladding parameters. The microstructure and the element distribution of cladding layer were analyzed by means of optical microscope （OM）, energy dispersive spectroscopy （EDS） and scanning electron microscopy （SEM）, and the corrosion rates of the cladding layer and base metal were tested by using weight loss method. The results show that the cladding layer on small hole＇s surface ofAISI8630 with high performance and no defect can be achieved by using optimized process parameters. The microstructure of the cladding layer is composed of columnar anstenite, dendrites and interdendritic eutectic, the fusion zone is plane crystal and the HAZ is columnar crystal and isometric crystal. The contents of alloying elements increase rapidly from the matrix to the cladding layer, and the contents of alloying elements in cladding iayor is more uniform. Incone1625 alloy has good corrosion resistance, and the corrosion rate of Incone1625 is about 1/6-1/5 of that ofAISI8630. The corrosion resistance of the sample with smaU boles improves significantly after cladding.