共查询到20条相似文献,搜索用时 62 毫秒
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基于计算机技术在焊接领域的应用现状,利用焊接电信号采集系统和光谱仪,基于Labview软件所设计的程序,实现同步采集,并把在每个时刻采集到的焊接电流,电弧电压波形信号及光谱仪采集到的光谱信息都在Labview的界面上同步显示,通过对两组药芯焊丝进行不同参数下熔化极气体保护焊药芯焊丝分析试验的同步采集,结合光谱信息、电信号及其前后时刻状态对药芯焊丝的典型熔滴过渡状态进行了分析。 相似文献
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研制一种Fe-B-Nb-Ni系钻杆耐磨带堆焊药芯焊丝,采用CO2气体保护堆焊方法,制备Fe-B-Nb-Ni耐磨堆焊合金,利用OM,SEM,XRD等方法对堆焊合金的显微组织进行了观察分析,对堆焊层的硬度及耐磨性能进行了测试分析.结果表明,Fe-B-Nb-Ni堆焊合金耐磨性能比国外某进口药芯焊丝提高了约37%,其宏观硬度值达到HRC60.5~62.2.Fe-B-Nb-Ni堆焊合金的显微组织为马氏体+铁素体+少量渗碳体+颗粒状NbC+包晶Fe3(B,C)+共晶Fe23(B,C)6、Fe3(B,C)+少量共晶Fe2B相,其中NbC硬质颗粒弥散的分布于基体中,基体中的马氏体组织具有优异的强度和耐磨性,起到了很好的耐磨骨架的作用.Fe-B-Nb-Ni堆焊合金的磨损机理主要是犁沟式微切削和局部的硬质相剥落. 相似文献
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采用汉诺威电弧质量分析仪、高速摄像机和激光粒度仪等研究了不锈钢药芯焊丝中铁粉/长石比对不锈钢药芯焊丝电弧稳定性、焊接烟尘平均颗粒尺寸、烟尘中Cr(Ⅵ)含量及其生成率.结果表明,短路过渡生成的焊接烟尘平均颗粒尺寸比粒状过渡小,烟尘中Cr(Ⅵ)/总Cr(n/N)的比值大;在同一焊接参数下,当药芯中铁粉/长石比例在1.8时,短路过渡时间最短为1033μs,焊接电弧稳定、焊接烟尘颗粒平均尺寸为1154 nm, Cr(Ⅵ)的含量及Cr(Ⅵ)/总Cr(n/N)的比最小,分别为1555.8 mg/kg和24%. 相似文献
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《电焊机》2015,(9)
在Cr13马氏体不锈钢药芯焊丝中添加2%铌铁、2%钒铁和5%氮化铬进行埋弧堆焊,研究氮合金化对堆焊层组织和耐磨性的影响。堆焊层试样分别在450℃、480℃、500℃、520℃、540℃、560℃和600℃下进行焊后回火处理,研究回火温度对堆焊层组织和耐磨性的影响。结果表明,焊态下硬面合金组织由马氏体、残余奥氏体和分布在基体上的碳氮化物组成。加入铌、钒和氮化铬后,组织的晶粒得到细化,耐磨性也随之提高。回火热处理使基体晶内及晶界弥散析出球状第二相粒子(Nb、V、Cr)x(C、N)y,随着回火温度的升高,氮合金化硬面合金中第二相粒子的数量先略有下降,再逐渐增加,随后急剧减少,耐磨性也相应改变。540℃时试样磨损量最小,耐磨性最佳,当回火温度升至600℃时,第二相粒子数量减少,耐磨性最差。 相似文献
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《Science & Technology of Welding & Joining》2013,18(3):155-158
AbstractTest techniques using unloading compliance single specimens to determine crack opening displacement (COD) resistance curves for flux cored arc welded joints were investigated in detail. Computer based methods for data acquisition and processing were incorporated in the test procedure. The causes of the shorter calculated crack length in comparison with the length measured according to unloading compliance single specimen techniques were studied, and the counter measures used to correct the crack length were analysed. The COD resistance curves for YJ657 basic flux cored wire (FCW) weld metal and joint line regions were then obtained using these techniques. The correlation coefficient using the least squares method to fit the curves was greater than 0.99. The results showed that the present test system and computer based data acquisition and processing techniques offered advantages such as flexibility of operation, stability of performance, and high accuracy when they were used to measure the COD resistance curves for FCW welded joints. The test results also indicated that the characteristic value of fracture toughness (extrapolated COD at zero crack length) for the YJ657 basic FCW weld metal and joint lines at 253 K was greater than 0.1 mm, indicating high toughness. This was because the weld metal microstructure consisted of a large proportion of acicular ferrite plates which were in different orientations and therefore able to deflect propagating cleavage cracks. 相似文献
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采用Fe-Cr-Nb-C堆焊合金体系,通过大量试验研制出焊接工艺性能和力学性能良好的无渣含铌自保护药芯焊丝.结果表明,在药芯中不添加任何造渣剂的情况下,药芯中各组分含量(质量分数)锰铁为12%、硅铁为6%、石墨为8%、钛铁为4%且其它组分合适时,自保护药芯焊丝的焊接工艺性能良好;该堆焊层组织由奥氏体、少量马氏体、一次碳化物及共晶物组成,随着铌含量的增加,硬度值先降后增,在铌铁含量3%时,最低硬度值为41.1 HRC.在碳含量有限的条件下,铌在焊接过程中形成碳化物质点,一方面增加了含铌硬质相,另一方面对碳化铬的形成造成影响. 相似文献
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Various fluorides, CaF2, Na3AlF6, K2SiF6, MnF3, and MgF2, were added to rutile-type flux cored wires at concentrations of 1.8–2.3% and their effects on hydrogen reduction in weld
metals were studied. All the fluorides reduced the hydrogen content but there were differences in the levels of reduction
among the wires; CaF2 showed the greatest reduction and MnF3 showed the least. The hydrogen content in the weld metals was not influenced by the fluorine formed in the arc but by the
slag basicity due to the small amount of fluorides added. The weld metal with higher slag basicities had a lower hydrogen
content. The effects of fluorides on the arc stability, weld metal hardness, and microstructure were also examined. Because
of the higher ionization potential of Mn, the wire containing MnF3 had the most unstable arc during welding. The wire containing MnF3 also produced a lower weld metal hardness than the other wires owing to its lower weld metal hardenability due to the greater
oxidation loss of the C, Si, and Mn elements during welding. 相似文献