全位置自保护耐磨堆焊药芯焊丝研制

发布时间：2018-01-04 14:20

本文关键词：全位置自保护耐磨堆焊药芯焊丝研制　出处：《机械科学研究总院》2015年硕士论文　论文类型：学位论文

【摘要】：用于耐磨堆焊的全位置自保护药芯焊丝在实际生产中需求很大,尤其野外作业的大型工件和复杂结构件现场堆焊修复时,需要在各种位置堆焊,但目前国内市场没有此类焊丝应用。因此,开发全位置自保护耐磨堆焊药芯焊丝成为亟待解决的重要问题。本文针对用于全位置堆焊的自保护药芯焊丝展开研究,开发了堆焊工艺性能和使用性能良好的药芯焊丝,同时研究了焊接规范对工艺性能的影响,为本焊丝堆焊制定了合理的规范参数。本文焊丝渣系研究以实现自保护和全位置堆焊为主要目的,通过渣-气-合金元素联合保护实现自保护,通过减小电弧长度、调整熔渣物理性能使焊丝适应全位置堆焊。经过配方试验,获得了药粉组分及含量对渣系主要工艺性能的影响。研究表明,药粉中添加45%-55%的氟化物和4%-8%的碳酸盐能实现良好的造渣、造气保护作用,氟化物中的BaF2适应短电弧燃烧,有利于全位置堆焊;药粉中添加8%-10%Al和4%-6%稀土时脱氧固氮效果显著;药粉中MgO、ZrO2等高熔点氧化物含量在4%-5%时,能有效改善熔渣物理性能,增强焊丝的全位置堆焊适应性。通过研究ZrO2和Al-Mg对脱渣性的影响,获得了脱渣良好的ZrO2和Al-Mg组分含量,优化了渣系配方。焊接规范影响工艺性能的研究表明,本焊丝直流正接时电弧稳定性更高、焊接飞溅更小,工艺性能优于直流反接;适合本焊丝堆焊的参数范围为U=(22-27)V,I=(220-270)A,此参数范围内堆焊时,熔滴过渡模式为弧桥并存过渡,电弧稳定性好、飞溅小。在焊丝获得良好工艺性能的基础上,本文确定的堆焊合金系为Fe-Cr-Mn-Si-Al系。通过分析研究堆焊合金成分对金相组织和硬度的影响关系,获得的堆焊熔敷金属组织有三类:M+B+δ-F、M+B、M+B+A,堆焊层硬度在HRC32-58之间。本文研制的药芯焊丝自保护效果和全位置堆焊性良好,焊接电弧稳定,飞溅小,容易脱渣,已成功应用于轨道辙岔的在线堆焊修复。
[Abstract]:Full-position self-shielded flux-cored wire used in wear-resistant surfacing welding is very required in actual production, especially in field work of large workpiece and complex structural parts in situ surfacing repair, need to surfacing in various positions. But at present the domestic market does not have this kind of welding wire application. It is an important problem to develop all position self-protective flux-cored wire for wear-resistant surfacing welding. In this paper, the research of self-shielded flux-cored wire for all-position surfacing welding is carried out. The flux-cored wire with good performance was developed, and the influence of welding specification on the process performance was studied. The main purpose of this paper is to realize self-protection and all-position surfacing welding. The self-protection is realized by slag gas-alloy element joint protection. By reducing the arc length and adjusting the physical properties of the slag to suit the all-position surfacing welding, the effects of the composition and content of the powder on the main technological properties of the slag system were obtained through the formula test. The addition of 45% to 55% fluoride and 4% to 8% carbonate into the powder can achieve good slagging and gas protection. The BaF2 in fluoride is suitable for short arc combustion and is favorable for all position surfacing welding. The deoxynitrogen-fixing effect was remarkable when 8% -10 Al and 4% -6% rare earth were added to the powder. The physical properties of the slag can be effectively improved when the content of MgO _ 2O _ 2 and ZrO _ 2 oxides at the same melting point is between 4% and 5%. By studying the effect of ZrO2 and Al-Mg on the slag removal properties, a good content of ZrO2 and Al-Mg components was obtained. The study on the influence of welding specification on the process performance shows that the welding wire has higher arc stability and smaller welding spatter, and the process performance is better than that of DC reverse connection. The parameter range suitable for surfacing welding of this welding wire is Uttrium 22-27V / Igna 220-270A, and the droplet transfer mode is arc bridge coexisting transition, and arc stability is good when surfacing welding is within this parameter range. Small spatter. On the basis of welding wire to obtain good process performance. In this paper, the hardfacing alloy system is Fe-Cr-Mn-Si-Al system. The influence of the composition of the surfacing alloy on the microstructure and hardness of the hardfacing alloy is studied. The deposited metal structures obtained by surfacing welding consist of three types: M B 未 -F C M B B A. The hardness of surfacing layer is between HRC32-58. The flux-cored wire developed in this paper has good self-protective effect and all-position surfacing property, stable welding arc, small spatter and easy slag removal. It has been successfully applied to the on-line surfacing repair of track switch.
【学位授予单位】：机械科学研究总院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG422.3

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