摘要本文通过调整自保护药芯焊丝配方中铝的含量，得到两个含铝量不同的两道焊 缝。通过估算可以得到，缝中的铝含量分别：0。5％和 1。25％。通过试验研究 Al 对夹 杂物形成的种类、尺寸、大小等特征的影响。此外分析铁基堆焊夹杂物的分布情况。83344

采用金相法和扫描电镜法，对未腐蚀和腐蚀后的样品进行观察。可以看到铝含量 不同的两条焊缝种的夹杂物分布、形态、尺寸都有不同。高铝焊缝中的夹杂物数量较 少、尺寸较大，呈现为多边形。通过 EDS 分析可得此夹杂物为 AlN。由于这种夹杂 物有棱角，对基体有着割裂作用，所以不利于焊缝的韧性。低铝焊缝的夹杂物尺寸较 小，呈现为圆形，通过 EDS 分析可得此夹杂物为 Al2O3 夹杂物。这种夹杂物可做形 核质点，促进晶粒的细化，提高焊缝的韧性。此外对两种焊缝的硬度做了测定，两者 的硬度都在 55HRC 左右。

毕业论文关键字：夹杂物；自保护药芯焊丝；铁基堆焊合金

Abstract In this paper, I get two different weld joint which with different aluminum content by adjusting the content of aluminum in Self-protection flux cored wire。 By the test we can estimate that the content of aluminum in two weld joint is 0。5% and 1。25%。 THRCough the experiment, we study on that how the content of aluminum affect the variety of inclusions, the formation of inclusions, the size of inclusions and the characteristics of inclusions。 In addition we analyzed the distribution of iron-based welding inclusions。

By metallographic test and sem the samples which are compared with that whether they are free of corrosion。 You can see that the distribution of inclusions, the shape, the size of inclusions are different in two weld joint。 In the weld joint which with high content of aluminum, the inclusion is less, larger and appears as a polygon。 By EDS test, we get that the inclusion is AlN。 Due to the angular of this inclusion, it has a split on the matrix, so it will reduce the toughness of the weld。 In the weld joint which with low content of aluminum, the inclusion is smaller and appears as a roundness。 THRCough the EDS test we get that the inclusion is Al2O3。 This inclusion can act as nucleation particles, promote the grain refinement and improve the toughness of the weld。 Also we test the hardness of two weld joint, the results showed that the hardness of weld seam with high content of aluminum is about 55 HRC, so as the low content of aluminum。

Keywords: Inclusions; Self-protection flux cored wire; Iron-based hardfacing alloy

目录

第一章 绪论 1

1。1 堆焊用自保护药芯焊丝的研究 1

1。1。1 堆焊概述 1

1。1。2 自保护药芯焊丝的概述 1

1。1。3 堆焊用药芯焊丝 3

1。2 夹杂物分析技术 4

1。2。1 金相法 4

1。2。2 电解提取夹杂物法 6

1。3。3 RTO 金属包埋切片表征法 7

1。3 本课题研究的内容和意义 8

1。3。1 研究内容 8

1。3。2 期望与可行性计划 8

第二章 试验材料与内容 9

2。1 试验材料与设备 9

2。1。1 药芯焊丝成分 9

2。1。2 药芯焊丝的制备过程 10