摘要铁基堆焊合金不仅价格低廉，品种多，而且可以调整成分和组织以满足各种如强 度、韧性、耐磨性、耐蚀性、耐热性和耐冲击性等性能要求，是应用范围最广泛的堆 焊合金之一。随着现代工业的飞速发展，堆焊技术与再制造技术的重要性也逐步显现， 为我国经济发展做出了越来越大的贡献。本课题组展开对铁基堆焊合金夹杂物中硅的 研究，以期分析得出一个最合适的硅含量，为堆焊产业的进一步发展而贡献力量，也 为我国再制造产业的发展与进步而努力。80637

本文讨论了硅含量的不同对堆焊合金夹杂物尺寸、分布、形态的影响，讨论了 Si 对夹杂物析出冶金行为的影响以及 Si 在夹杂物物理冶金行为中作用的分析，试验 结果表明：

1．随着 Si 含量的增加，在其中的 Si 含量达到 18%前，试样中较大夹杂物的尺 寸逐渐增大，而当 Si 含量达到 18%时，试样中夹杂物的分布较均匀，平均尺寸较小。 而当硅含量继续增加至 24%时，试样中夹杂物尺寸再次增大。硅含量越高，对熔池的 保护和后期的帮助就越大。堆焊合金中整体的含氧量随着硅含量的提高而降低。

2．当向试样中添加 18%的 Si 时，焊缝合金组织的夹杂物形状变为圆钝形，不会 引起合金组织的性能降低。焊缝合金组织中，在硅含量过量前，随着硅含量的提升， 碳化物逐渐有序排列，向焊丝中添加更多的硅，堆焊层组织从典型的网状组织转变为 过共晶组织，促使碳化物析出在合金中形成弥散强化。加入适量的硅，可以细化合金 的组织，使碳化物的平均尺寸变小，从而提高合金的抗裂性能。

3．硅含量逐渐提高的过程中，堆焊合金的硬度呈先增高，后降低的趋势。当硅 添加量为 18%时，堆焊合金的硬度最高。

毕业论文关键词：硅；夹杂物；铁基堆焊合金；组织；堆焊

Abstract Iron-based hardfacing alloys (iron-based hardfacing alloy) only low prices, many varieties, and can adjust the composition and organization to meet various such as strength, toughness, wear resistance, corrosion resistance, heat resistance, and resistant to impact etc。 performance requirements, is the most extensive scope of application heap welding, one of Kim。 With the rapid development of modern industry, welding technology and remanufacturing technology is of importance also gradually revealed, for the economic development of our country made more and more contribution。 The research group started research on iron-based hardfacing alloy inclusions in silicon, to analysis a most suitable silicon content, for the welding industry The further development of the contribution force, but also for the development of China's remanufacturing industry and strive to progress。

This paper discusses the silicon content of different of hardfacing alloy inclusion size, distribution, influence the morphology, discusses the role and the effect of Si on inclusion precipitation metallurgical behavior and Si in the inclusion behavior of physical metallurgy analysis。 The test results show that:

1。With the increase of Si content, before the Si content was up to 18%, larger inclusions in the sample size increases, and when the Si content was up to 18%, with uniform distribution of inclusion in the sample, and smaller average size。 And when the silicon content continued to increase up to 24%, sample size of inclusions is increased again。 Higher silicon content, larger with the help of the molten pool protection and the later。 Surfacing alloy in the overall oxygen decreases with the increase of silicon content。

2。When 18% is added to the sample of Si, the weld microstructure of inclusion shape change is blunt shape, will not cause the reducing performance of the microstructure of the alloy。 Weld microstructure and silicon content in excess of, with upgrading of the silicon content and carbide gradual and orderly arrangement, to the wire in adding more silicon and structure of the surfacing layer from typical reticular tissue change for eutectic structure, promote the precipitation of carbides in alloy Nagata Narumi strengthening。 Adding proper amount of silicon, can refinement, the carbide of average size smaller, so as to improve the crack resistance of the alloy。