【作者】 黄春明；

【导师】 李午申；

【作者基本信息】 天津大学 ， 材料加工工程， 2008， 硕士

【摘要】 自保护药芯焊丝是近几年发展较快的新型焊接材料,已广泛应用于输油输气管线、桥梁、造船、海洋平台、建筑等领域,并且能够适应野外较为恶劣的工作环境。本文是以多种氟化物-Fe₂O₃-Al-Mg碱性渣系为研究对象,通过工艺性能试验、力学性能试验、金相组织分析等方法,对X80管线钢用自保护药芯焊丝的渣系和低温韧性进行了细致的研究。自保护药芯焊丝的药粉粒度对焊丝焊接工艺性能有重大的影响。本文对焊丝药粉进行预处理的试验研究发现,经过预处理的药芯粉,使焊接工艺性能大大改善。渣系是研究自保护药芯焊丝的一个重要方面,渣起着主要的保护作用。本文中选用的自保护药芯焊丝的渣系主要是多种氟化物、氧化铁及铝镁系,其中氟化物在造渣的同时也有部分能汽化在熔融金属周围形成氟化物气团,隔绝熔化金属与空气的接触;铝镁有较强的脱氧固氮作用,是很好的脱氧剂和固氮剂,能够有效地防止气孔的产生。本文通过调整药芯配方的成分及其含量,来研究熔渣的粘度、覆盖性、脱渣性、润湿性等对焊接的工艺性能产生的影响。熔敷金属的力学性能是研究自保护药芯焊丝的重要指标,尤其是低温韧性的提高更是研究的关键。本文通过在合金系中加入Ni和稀土元素的同时控制Al的含量来进行试验,对熔敷金属的屈服强度、抗拉强度及低温冲击韧性进行研究,并且对熔敷金属的成分、组织及其夹杂物进行分析,发现Al对韧性的恶化有显著的影响。通过对自制焊丝焊接试验结果的研究,寻找加入各成分及其含量对渣系和韧性的影响规律,合理调整配方,使自保护药芯焊丝的质量得到进一步的优化。更多还原

【Abstract】 The self-shielded flux cored wire is a new type of welding materials, which has developed rapidly in recent years and used widely in oil pipelines, bridges, shipbuilding, offshore platforms, buildings and other fields. In this article, the component of the alkaline slag based on fluorides-Fe₂O₃-Al-Mg and the toughness of the deposited metal are the study objects. Then the research on self-shielded flux cored wire and the low-temperature toughness about X80 pipeline steel is carried out though the technology performance tests, mechanical properties tests and microstructure metallography analysis.The powder size used in producing the self-shielded flux cored wire is very important to the stability of the welding process. This paper indicates that pretreatment of the flux cored powder can greatly improve the welding technology performance.Slag system is an important aspect in the study of the self-shielded flux-cored wire. Because it is a primary protection to the high-temperature molten metal. In this experiment, the component of the flux core are fluorides ,Fe2O3 andAl-Mg alloy, parts of the fluorides can vaporize to formation fluoride air mass around the molten metal to isolates molten metal from the air ; Al-Mg is a good deoxidizer and denitrifier, can effectively prevent the formation of the pores. There will be a research on the adjusting of the composition and amount of the flux core, and study the impact on the technology performance of the composition, cover, viscosity, slag-detachability, wettability of the slag in welding process.The mechanical properties of the deposited metal are the important issues and raising the low-temperature toughness is the key problem. In this experiment ,adding Ni and rare earth elements to the flux core, and control Al amount at the same time, then carry out the test of yield strength, tensile strength and low-temperature impact toughness of the deposited metal, and give the analysis to the composition, structure and its inclusion, conclude that Al have a marked impact on the toughness deterioration.According to the the experimental results of the slag system and the toughenss to look for the law of the various components and the amount of the flux core. Then the quality of flux-cored wire will be further optimized through adjusting the formula rationally.更多还原