共查询到17条相似文献,搜索用时 78 毫秒
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扩散氢是导致高强钢焊接接头产生冷裂纹的主要原因之一,为降低焊条熔敷金属中扩散氢含量,选择和调整药皮组分以降低扩散氢含量,本文通过排液测氢法测定扩散氢,并建立起碱性焊条药皮组分与扩散氢含量之间的数学模型,通过计算机绘制的扩散氢等值线图分析了药皮组分及其相互作用对扩散氢含量影响的规律;提出了预报和控制扩散氢的方法,这对焊条设计具有指导意义。 相似文献
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通过添加不同量的钛铁到药芯焊丝中,并在不同保护气焊接的条件下,研究其对熔敷金属扩散氢的逸出和含量的影响.结果表明,保护气体氧化性的增加可以降低熔敷金属扩散氢,而保护气还原性的增加,则熔敷金属扩散氢含量也会相应增加;在药芯焊丝中加入一定量的钛铁,一方面TiO,Ti(C,N)颗粒会在熔敷金属中形成的不可逆氢陷阱,对氢产生捕获作用,可以降低熔敷金属扩散氢;同时,加入的钛铁会提高电弧气氛的还原性,这样会增加熔敷金属的扩散氢,所以适量的添加钛铁,使钛铁对焊接气氛的氧化性的影响和形成不可逆氢陷阱的作用之间合理的结合,能达到理想的降氢效果.Abstract: The effects of Ti content on diffusible hydrogen escape characteristic of deposited metal of flux cored wire were investigated by adding different quantities of Ti-Fe and in different protecting gas conditions. The results show that the oxidative susceptibility of protecting gas can decrease the diffusible hydrogen of deposited metal, and the grains of Ti and Ti(C,N) which exhibit irreversible hydrogen traps can also decrease the diffusible hydrogen of deposited metal. The rational adding Ti-Fe, which harmonized the oxidative susceptibility of welding atmosphere and formed the irreversible hydrogen traps, could obviously decrease the diffusible hydrogen of deposited metal. 相似文献
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《机械制造文摘:焊接分册》2019,(2)
探究了GB/T 3965—2012《熔敷金属中扩散氢测定方法》中载气热提取法收集条件对测定扩散氢含量的影响,并与水银法进行了对比。研究结果表明,样本炉温设定为400℃,A型试块的内部温度大约在51 min时稳定在358℃左右,B型试块内部温度大约在27 min时稳定在391℃左右;载气热提取法电信号曲线收集结束点的电信号及斜率均接近0时获得的结果与水银法具有较好的一致性。 相似文献
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探究了GB/T 3965—2012《熔敷金属中扩散氢测定方法》中载气热提取法收集条件对测定扩散氢含量的影响,并与水银法进行了对比。研究结果表明,样本炉温设定为400℃,A型试块的内部温度大约在51 min时稳定在358℃左右,B型试块内部温度大约在27 min时稳定在391℃左右;载气热提取法电信号曲线收集结束点的电信号及斜率均接近0时获得的结果与水银法具有较好的一致性。 相似文献
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《Science & Technology of Welding & Joining》2013,18(5):408-413
AbstractA systematic study was conducted to examine the effectiveness of pre- and post-heating to bring down the diffusible hydrogen (HD) content in the welds to levels that are unlikely to cause cracking. Specimens for HD measurement were prepared as per ISO standard 3690, and the measurement was carried out using standard mercury method and the newly developed hot extraction technique, which uses a hydrogen sensor. Results show that pre- and post-heating of the weld at lower temperatures are more effective than preheating alone at higher temperatures to bring down the HD content in the welds. Results also indicate that if the HD content of welding consumable is known, it is possible to choose the preheat and post-heat temperatures that will bring down the HD content remaining in the weld to sufficiently low levels so that danger of delayed cracking is minimum. Such information can help to optimise the pre- and post-heating requirements during weld fabrication, resulting in substantial energy savings. 相似文献
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通过拉伸、冲击试验,利用金相显微镜、透射电镜、扫描电镜和电子背散射衍射技术分析了铬含量对耐候钢熔敷金属组织和韧性的影响.结果表明,两种熔敷金属的组织均为粒状贝氏体、针状铁素体和少量板条贝氏体.两种熔敷金属冲击韧性良好.与含1.0% Cr(质量分数)熔敷金属相比,含1.41% Cr熔敷金属中粒状贝氏体含量升高,针状铁素体含量降低,屈服强度增加6%,抗拉强度增加9%,冲击吸收功降低56%.此外,含1.41%Cr熔敷金属中M-A组元含量升高、大角度晶界比例下降、平均有效晶粒尺寸增加,显微裂纹的形核几率增加,裂纹扩展阻力降低,导致其韧性降低. 相似文献