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Investigations were carried out into the relationship between the shape and composition of non-metallic inclusions, formed in the weld metal in welding E36 and AB steels with low-alloy wires under agglomerated fluxes of the MgO–CaF2–Al2O3–SiO2 system, and the composition of the flux. It is shown that the increase in the fraction of circular non-metallic inclusions and the reduction of the fraction of elongated inclusions in the weld metal, like the reduction of the mean size of the inclusions, increase the impact work of the weld metal at the test temperature of ? 40°C. 相似文献
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大理石、萤石对不锈钢焊条熔滴过渡及熔滴中夹杂物的影响 总被引:1,自引:1,他引:0
采用水中收集熔滴、光学显微分析、电子扫描能谱分析、计算机图像分析及平板堆焊等试验方法,分别研究了大理石、萤石对不锈钢焊条熔熵过渡行为,以及它们对熔滴中非金属夹杂物及焊缝中气孔的影响。结果表明焊缝和熔滴中的非金属夹杂物呈圆球形,它们是熔滴反应区化学反应的产物,属“内生”性质;药皮中大理石含量增大时,熔滴尺寸与熔滴中夹杂物含量的波动变化存在对应关系,焊条工艺性变差,焊缝中气孔敏感性未减小;药皮中氟化稀土和萤石比值增大,熔滴细化,熔滴中夹杂物含量增大,焊条工艺性能有所改善,焊缝中气孔倾向未减小。 相似文献
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Yu N Saraev L I Makarova V N Grishkov V G Polnov N V Kirilova 《Welding International》2013,27(1):54-55
This paper discusses the relationship between the concentration of oxygen in the weld metal deposit – produced with basic- and rutile-shielded electrodes – and the size of non-metallic inclusions. Furthermore, this paper presents a mathematical formula that allows one to calculate the diameter of non-metallic inclusion in the metal weld deposit depending on the concentration of oxygen in MWD. 相似文献
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利用OM和SEM研究了X100管线钢焊接接头的微观组织,并利用EDS分析接头中的非金属夹杂物种类及成分。结果表明,实验用X100管线钢焊接接头由针状铁素体、粒状贝氏体和M/A岛组成;焊缝金属中含有MnS,Si的氧化物和Al的氧化物及Al-Mg-O和Ca-Al-O-S系夹杂物。焊接接头氢致开裂敏感性较高,焊缝金属中的非金属夹杂物及硬脆M/A组元与基体之间的界面和应力导致氢致裂纹的萌生,并沿粗大的贝氏体晶粒扩展。 相似文献
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N. A. Kozyrev R. E. Kryukov N. E. Kryukov I. N. Kovalskiy V. F. Igushev 《Welding International》2016,30(4):325-328
The technological aspects of adding carbon–fluorine-containing additions to AN-348, AN-60 and AN-67 fluxes in welding 09G2S steel are investigated. It is shown that the addition decreases the total oxygen content of the welded joint, lowers the degree of contamination with oxide non-metallic inclusions and the level of gas saturation of the weld metal, and increases the mechanical properties and impact toughness of the welded joints. The carbon concentration of the welded joint remains similar to that of the parent metal. 相似文献
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1 INTRODUCTIONAsoneofthelighteststructurematerials ,mag nesiumalloysofferlightmass(ρ<2 g·cm- 3) ,specif icstrength (higherthanthatofthealuminumalloysandsteels) ,specificstiffness ,excellentmachinabili ty ,superiordampingandmagneticshieldingcapaci ties,whichleadstoagrowinginterestinmagnesiumanditsalloys .Inrecentyears ,magnesiumalloyshavebeenwidelyusedinaviation ,spaceflight,automobileandelectronicsindustries[1] .Since 1990 stheirappli cationhassteadilyextendedanditispredictedthatitwill… 相似文献
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在相同热输入下分别采用熔化极活性气体保护焊(MAG)和钨极氩弧焊(TIG)进行1 000 MPa级熔敷金属试验,通过光学显微镜、透射电镜及断口分析等手段研究焊接方法对其组织和性能的影响. 结果表明,MAG焊熔敷效率明显高于TIG焊,MAG焊中出现了明显的"指状熔深". MAG焊熔敷金属及道间热影响区组织明显较TIG焊粗化. TIG焊熔敷金属组织细化、分布取向多样化且均匀分布的较多残余奥氏体是TIG焊低温冲击韧性优异的原因之一;MAG焊中生成大量非金属夹杂物易成为解理断裂起裂源,是导致熔敷金属冲击韧性恶化的因素之一. TIG焊力学性能明显优于MAG焊,这与焊接方法所导致的组织构成及夹杂物有直接关系. 相似文献
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N. E. Kryukov O. E. Kozyreva R. E. Kryukov N. A. Kozyrev A. A. Usol’Tsev 《Welding International》2018,32(10):672-677
ABSTRACTThe properties of a welding flux based on the silicomanganese slag are investigated. The flux is produced using the slag formed in the production of silicomanganese with different ratios of the slag fractions and different content of the water glass in the flux addition. The addition of up to 20–30% dust fraction of the silicomanganese slag to the composition of the flux results in excellent mechanical properties of specimens taken from the welded plates. The FD-UFS addition reduces the extent of contamination with non-metallic inclusions and reduces the size and amount of these inclusions. The optimum content of the water glass in the flux (up to 20–30%) was determined. Consequently, the resultant mechanical properties of the specimens taken from the welded plates are very high. 相似文献
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钢包底吹氩工艺是一种经济实用且简单易行的精炼方法,通过实验室物理模拟确定出膨胀合金4J43在底吹氩工艺中氩气流量应控制在3~7 L/min之间。在该流量范围内,合金液的混匀时间随氩气流量的增加而减少。在合适的吹氩参数下进行工业生产,实验结果表明:吹氩工艺对4J43膨胀合金中氧元素及夹杂物的去除效果明显。当氩气流量为5 L/min时,与未吹氩相比合金中氧元素含量下降56.98%,非金属夹杂物总量减少46.43%,合金中大尺寸夹杂物数量明显减少,合金在室温下的各项力学性能与同组相比均得到很大提高。 相似文献
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The effect of the chemical activity of flux on the properties of deposited metal of Mn–Ni–Mo–V steels, produced by electroslag welding and electroslag remelting, is discussed. It is shown that an increase in the chemical activity of flux by increasing its silica content to 16–24% (FTs-21 flux) in the remelted metal increases the fraction of easily deformed non-metallic oxide inclusions and the number of zones with reduced hardness in the structure of the metal. This increases the elasticity properties and strain capacity of the metal in the process of relaxation of welding stresses and in the formation of the required mechanical properties of the welded joints after final heat treatment. Also, the risk of formation of reheat cracks in the electroslag welded joints is reduced. 相似文献
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以金红石型铬镍奥氏体不锈钢焊条焊缝为研究对象,以气泡浮出速度理论为基础,综合介绍了不锈钢焊缝中气孔形成机理研究的几种观点:药皮中水分影响理论、熔滴中非金属夹杂物影响理论、焊缝金属凝固模式影响理论和熔滴过渡形态影响理论,为后续研究及工程应用提供了必要的理论依据。 相似文献
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Abstract The effect of heavy rare earth metals (REM) on the toughness of low alloy steel weld metal has been studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and an energy dispersion X-ray spectrometer (EDX). The results show that by adopting an appropriate flux coating and welding procedure, a small amount of heavy REM (about 10ppm) can be transferred to weld metal, thus reducing area density and area percentage of inclusions and improving the low temperature toughness of the weld metal. Since a decrease in inclusion content correlates well with an increase in low temperature toughness, it can be considered that cleaning and modification of weld metal by heavy REM greatly contributes to improving low temperature toughness. In addition, an examination of types of inclusions has been carried out. 相似文献
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Influence of Ti on non-metallic inclusion formation and acicular ferrite nucleation in high-strength low-alloy steel weld metals 总被引:1,自引:0,他引:1
Yongjoon Kang Jihun Jang Joo Hyun Park Changhee Lee 《Metals and Materials International》2014,20(1):119-127
The phase transition behaviors of non-metallic inclusions as a function of Ti content were investigated by monitoring changes in the microstructure and mechanical properties of high-strength low-alloy steel multipass weld metals. Weld metals with Ti contents ranging from 0.007 to 0.17 wt% were prepared using a gas metal arc welding process. The inclusion analysis was performed based on thermodynamic calculations and transmission electron microscopy, accompanied by energy-dispersive spectrometry and selected area electron diffraction. With increase in the Ti content of weld metals, the chaotic arrangement of ferrite laths in the columnar zone was transited to a well aligned arrangement and the impact toughness of the weld metals drastically deteriorated in response to the decrease in the Mn content of the inclusion. The effective inclusion phase for intragranular nucleation contained considerable amounts of Mn and a Mn depleted zone was observed around the effective nucleant. 相似文献
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Chuan Liu Jiawei Yang Qinglei Ge Fei Gao Jiasheng Zou 《Science & Technology of Welding & Joining》2018,23(2):95-104
The effects of layered ultrasonic impact treatment (LUIT) on the mechanical properties of thick multi-pass weld were investigated. Two 55-mm thick multi-pass welding joints were prepared, one was treated with LUIT, and the other was joined with conventional welding method. Shear-punch test and Charpy impact test were used to examine the mechanical properties of both joints. Results show that LUIT can increase the strength of weld metal (WM), resulting in more uniform shear strength distribution across the treated WM and higher impact toughness of the WM. The mechanical properties improvement of WM attributes to the oxidation of metals induced by ultrasonic impact treatment, which increases the oxygen content in the WM and causes more non-metallic oxide inclusions, and then affects the grain growth behaviour of the subsequent beads, resulting in a fine-grained microstructure and improved strength and toughness of the WM. 相似文献
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The microstructure and fracture toughness of weld metal under Ti-free and Ti-containing different fluxes were investigated in this study.It was found that the trace element Ti of flux in submerged arc welding produced significant influence on the fracture toughness.The addition of 60 ppm Ti induced the sharp increase in J_(0.2) value from 232.78 to 364.08 kJ/m~2.Microstructure characterization revealed that a large number of oxide inclusions prompted the nucleation of acicular ferrites and refined grains,which improved the fracture toughness of Ti-containing weld metal greatly.Moreover,the crack propagation path was more tortuous and bifurcated due to the small amount of carbide precipitations along grain boundaries and blocky martensite-austenite islands for Ti-containing weld metal.Meanwhile,the large-angle grain boundaries caused crack deflection and increased the resistance of crack propagation compared to Ti-free weld metal. 相似文献
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用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X 射线能谱仪(EDAX)研究了重稀土元素对低合金钢焊缝金属韧性的影响.结果发现,采用适当的焊条药皮配方和焊接工艺可使重稀土元素微量过渡到焊缝金属中(约10ppm),减少了夹杂物的面密度和面积百分数,显著提高了焊缝金属的低温韧性。夹杂物的减少和低温韧性的提高有很好的对应关系,因此可以认为,重稀土元素对焊缝金属的净化和变质作用是提高焊缝低温韧性的主要原因。此外,还对焊缝金属中夹杂物的类型进行了较深入的鉴别。 相似文献