1、 湘潭大学工程硕士学位论文 摘 要 摘 要 表面堆焊可用于制造新零件，也可用于修复损坏零件的表面。在阀门密封面进行表面堆焊，可以提高阀门密封面的耐冲蚀、耐腐蚀、耐高温及抗刮伤等性能，不仅降低其生产成本，而且还提高阀门的寿命。本文基于1Cr13系阀门堆焊焊条的合金体系，通过改变渣系，利用金相显微镜、硬度计及磨粒磨损试验机等分析研究了不同渣系的堆焊焊条的工艺性能和堆焊层的组织、硬度和耐磨性，开发了两种适于高中压阀门密封面的新型耐磨堆焊焊条。本文通过比较这两种焊条的性能，得出它们之间的优劣所在，同时探讨药皮中各元素对焊条工艺性能和堆焊层的组织、硬度和耐磨性的影响，为生产和制造提供一定的参考价值。研究
2、结果表明：这两种堆焊焊条抗氧化、气孔和裂纹性强，脱渣性好以及其它工艺性能良好，同时克服了现有焊条熔渣厚等缺点，提高了焊条过渡效率，堆焊层硬度为4550HRC且耐磨性好。研究主要结论：1）低氢型焊条的抗氧化和抗裂性好，但引弧性尤其再引弧性较差，钛钙型焊条的引弧性及稳弧性好但抗裂性较差；低氢型焊条的熔渣覆盖性及脱渣性较差且焊缝成型一般而钛钙型焊条的则较好；低氢型焊条以短路形式过渡，飞溅率较小但发尘量较大而钛钙型焊条则以喷射形式过渡，飞溅率较大但发尘量较小。2）在低氢型焊条中，大理石/萤石值是解决其电弧稳定性、飞溅率及熔渣流动性的关键因素，调整萤石的含量能改变焊条的稳定性。3）硅铁、钛铁及石墨等脱氧
3、剂对脱渣有利，H、O比例协调时焊条的抗气孔及抗氧化性得到加强。在低氢型焊条中用MgO代替部分CaO后其脱渣性得到大幅度的改善。4）钛钙型焊条中金红石是影响裂纹的主要因素，其含量不可过大，同时钛铁矿含量要适宜，否则含量过大将引起气孔及脱渣性变差等缺点。关键词：关键词：阀门；1Cr13堆焊焊条；焊接工艺性能；显微组织；耐磨性 I湘潭大学工程硕士学位论文 Abstract Abstract The surface of valve sealing usually losses effectiveness due to abrasions,scuffing and pad wounds.To save
4、 resources and recover the valve rapidly and minimize the loss of the country and enterprises,we often do resurfacing welding and repair the damaged valves.The paper has studied the ingredient,hardness and wearing resistence of the resurfacing welding layer using the metallographical microscope,hard
5、ness,abrasive wear testing machine and other equipments,and has developed two new wear-resistant surfacing welding electrodes for the sealing surface of high and medium pressure valve,based on the hardfacing electrode with Cr13 system and by changing the slag system.The result of the research indica
6、tes:Two kinds of the welding electrodes have anti-oxidation,high porosity and cracks,slag off good,and other good procedure performance.At the same time they overcome the existing shortcomings like thick welding slag,and improve the transition efficiency of the electrode,and the hardness of the surfacing welding layer is HRC 4550 and wear resistance is well.This paper draws a conclution on their advantages between the two welding electrodes by comparing their performance,and provides reference v
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