共查询到19条相似文献,搜索用时 356 毫秒
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基于TiC、VC的高显微硬度,利用药皮中钛铁、钒铁、石墨等组分的高温电弧冶金反应在堆焊层中生成碳化物硬质相。系统研究了药皮组分对堆焊层硬度和合金元素过渡系数的影响,利用扫描电镜(SEM)、电子探针(EMPA)观察和分析了堆焊层中碳化物的分布、形貌和成分。结果表明:随着药皮中钛铁、钒铁、石墨组分的增加,堆焊层硬度提高,但当石墨组分超过12%时,堆焊层硬度下降。随着药皮中钛铁、钒铁、石墨组分增加,熔敷金属中Ti、V、C元素含量不断提高,Ti、V、C元素过渡系数提高,但V、C元素过渡系数分别在钒铁12%、石墨14%时达到最大。 相似文献
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堆焊合金中合金元素 Cr 和 V 与堆焊层中的 C 形成 Cr7C3及 VC 等硬质相,在此基础上加入B 元素,形成相应的 TiB2,可进一步增加其硬度和耐磨性;因此,在高 Cr 合金中加入 B4C 制成粉芯,用埋弧焊堆焊的方法得到合金,测量宏观硬度并且观察了显微组织。结果显示,随着 B4C 含量增加,试样中硬质相比例增加,提高了试样的硬度,一定程度上增加了耐磨性(B4C 含量1.5%-3.5%为宜);但 B4C 含量过高(B4C 含量达到3.0%左右),晶界偏析加大,易导致堆焊层开裂。 相似文献
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焊条药皮中采用石墨、钛铁、钒铁、钼铁等组分,通过电弧冶金反应生成具有高硬度的TiC、VC、MoC等碳化物颗粒,研制出具有硬度高、耐磨性好的耐磨堆焊焊条。探讨了焊条药皮中石墨、钛铁、钒铁、钼铁等组分含量对焊条工艺性及堆焊层硬度的影响。利用X射线衍射、光学显微镜(OM)和电子探针(EMPA)对堆焊层显微组织和碳化物形成进行了分析。研究结果表明,碳化物颗粒为TiC-VC-MoC复合碳化物颗粒,并且碳化物颗粒弥散分布在基体上。焊前不预热,焊后不缓冷连续堆焊不产生裂纹。堆焊层硬度达到HRC59以上,具有高的耐磨性,相对耐磨性优于D317焊条。 相似文献
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含钒耐磨堆焊合金的组织与性能 总被引:1,自引:0,他引:1
通过在Fe-Cr-C自保护金属芯堆焊焊丝中加入不同含量的钒(钒的质量分数分别为0.73%,2.3%,3.1%,4.1%),研究了钒对Fe-Cr-C堆焊合金微观组织、硬度及耐磨性的影响。试验结果表明,随钒含量的增加,堆焊合金组织的基体由奥氏体向奥氏体+马氏体转变,当钒的质量分数超过4%时,基体组织全部转变为马氏体;随钒含量的增加,堆焊合金组织中的初生碳化物由长条状、粗大直边六角状转变为球状或不规则形状,基体中析出大量弥散分布的二次碳化物;随钒含量的增加,堆焊合金的硬度和耐磨性亦相应提高。 相似文献
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采用PK-YD5Cr8Si3药芯焊丝CO2电弧焊工艺在T-1钢、STE690钢上进行了堆焊工艺试验研究,确定了合理的工艺规范,进行了耐磨试验,测试了堆焊层的硬度,观察分析了堆焊层金相组织。结果表明,PK-YD5Cr8Si3药芯焊丝抗裂性较好,且堆焊层的耐磨性较高,符合工厂对耐磨件修补的要求。 相似文献
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《机械工程学报(英文版)》2010,(6)
Welding spatter cause many problems during the welding process and this issue is particularly important for cellulose electrode welding.The hot flying spatter balls often deteriorate the working environment,and decrease the welding efficiency.Many factors affect the welding spatter,and metal transfer behavior is one of the main factors.Many studies concerning the spatter mechanism in arc welding process were made;most of them focused on the solid wire welding and the study on cellulose electrode is rarely reported.In this paper the metal transfer behavior and the weld spatter characteristics of three commercial cellulose electrodes were studied experimentally by using a high speed camera for visually capturing the metal transfer.The relationship between the metal transfer and the welding spatter was analyzed experimentally by comparing the spatter loss coefficient,which is for quantitative evaluation of welding spatter,with the statistical analysis of the large droplet transfer mode.The results showed that short circuiting transfer,large droplet spray transfer,fine droplet spray transfer and explosive transfer govern the metal transfer modes in cellulose electrode welding.Weld spatter occurred mainly in the deflection of large droplet process,explosive transfer process and fine droplet spraying process.Different metal transfer modes lead to different spatter.The deflection of large droplet and explosive transfer are the main factors of the spatter formation.Minimizing the droplet size and reducing the deflection of large droplet and explosive transfer leads to the reduction the amount of spatter in cellulose electrode welding. 相似文献
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针对残余应力、组织成分对再制造堆焊层质量的影响,运用仿激光焊技术,采用H13CrMoA焊丝,在变速箱主动轴上整周堆焊不同厚度的焊层,用X射线残余应力分析仪测试堆焊层表面的残余应力,电解抛光堆焊层,分析堆焊层的应力梯度和界面应力,通过X射线能谱仪(EDS)分析堆焊层界面处成分分布,用扫描电镜(SEM)观测其组织形貌,结果表明:堆焊层表面峰值应力为拉应力,且随厚度的增加变化不大;沿垂直于单条焊缝中心线至轴心线方向所测的应力存在一定应力梯度,A0和A1界面处残余拉应力较大,A2界面处为较小残余拉应力;堆焊层界面处组织成分分布较均匀。 相似文献
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人字齿轴辊自动堆焊机 总被引:1,自引:0,他引:1
目前能实现自动化堆焊设备少,且使用效果差、劳动强度大、能耗高,针对轴辊齿面硬度高、耐磨性好、耐疲劳性强和特殊的齿形要求,提出了基于堆焊技术和PLC技术人字齿轴辊自动堆焊机的设计思路,阐述了人字轴辊自动堆焊机的整体设计,介绍了自动堆焊机焊接系统、送丝装置、焊剂输送系统和工件回转机构等设计与制作过程。实践表明,该自动堆焊机具有运行稳定、加工的齿形多样、堆焊层质量高、能实现补焊和修复特点,并实现轴辊循环再利用。 相似文献
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为了研究汽车驱动桥壳表面损伤后的堆焊修复层能否满足再制造的要求,选用H13CrMoA和ER50-6焊丝并采用亚激光瞬间熔工艺,在汽车驱动桥壳片表面制备不同厚度的堆焊层。利用金属磁记忆检测仪和扫描电镜分析堆焊试样的应力分布和断面组织特征,同时测试堆焊试样的硬度并进行渗透、磁粉和X射线三种无损检测。结果表明:ER50-6堆焊试样的堆焊层与母材硬度相近,母材热影响区未发生局部软化,堆焊层与母材结合良好,不存在焊接缺陷和应力集中区,应力分布不均匀程度低于H13CrMoA堆焊试样。
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Liu Haiyun Li Zhuoxin Shi Yaowu College of Material Science Engineering Beijing University of Technology Beijing China 《机械工程学报(英文版)》2005,18(1):109-111
A high-speed photographic method is mainly used to analyze metal transfer of a cellulose covered electrode in the vertical down welding. The experimental results show that fine droplets spraying transfer and globular transfer are the dominant transfer characteristic. The large droplet spatter, especially the upwards spatter, is a particular phenomenon. It is found that the combination action of gas blow force, surface tension, gravitational force and electromagnetic force lead to globular transfer. Gravitational force and electromagnetic force, which hasten big droplet spatter, should not be neglected. 相似文献
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采用多元微合金化铸铁同质气焊丝对HT250铸铁板材进行了气焊研究,测试和分析了焊接接头的硬度、抗裂性和机械加工性能。研究结果表明:接头颜色和硬度与母材一致,焊缝组织为珠光体加小团状石墨,抗裂性能良好,机械加工性能优良。 相似文献
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SURFACING ELECTRODE WITH CRACKING RESISTANCE AND WEARABILITY 总被引:1,自引:0,他引:1
Yang Shanglei Lu Xueqin Lou Songnian Institute of Welding Shanghai Jiaotong University Shanghai China Zou Zengda School of Material Science Engineering Shandong University Jinan China 《机械工程学报(英文版)》2005,18(1):68-70
A new surfacing electrode is developed with cracking resistance and wearability based on high microhardness of TiC and VC, carbides of Ti and V are formed in deposited metal by means of high temperature arc metallurgic reaction. The results show the hardness of surfacing metal increases with the increase of ferrotitanium (Fe-Ti), ferrovanadium (Fe-V) and graphite in the coat. However, when graphite reaches the volume fraction of 11%, the hardness reaches its peak value, and when beyond 11%, the hardness falls off. As Fe-Ti, Fe-V and graphite increase, the cracking resistance of deposited metal and usability of electrode declines. Carbides are dispersedly distributed in the matrix structure. The matrix microstructure of deposited metal is lath martensite. Carbides present irregular block. When using the researched surfacing electrode to continue weld with non-preheated, no seeable crack or only a few micro-cracks can be observed in the surface of deposited metal. The hardness is above 60 HRC. The wear res 相似文献