共查询到20条相似文献,搜索用时 0 毫秒
1.
用粒径70~90nm大理石取代堆焊焊条D600R药皮中的微米大理石,制成纳米大理石焊条.利用汉诺威电弧质量分析仪对焊接过程中的电流电压和短路时间进行测试,获得微米大理石焊条和纳米大理石焊条的燃弧特征;通过焊接工艺试验、测氢试验、熔化温度测试、硬度试验、耐磨试验和微观分析,分别对两种焊条的工艺性能和力学性能进行分析.结果表明,用纳米大理石替代微米大理石可降低焊条药皮的熔化温度和堆焊层金属中的扩散氢含量;提高焊条的熔敷效率;降低焊条短路电压、短路电流概率密度和,在短路时间t12.05ms时间段内缩短累计短路时间;改善焊条操作性能;提高堆焊层金属硬度和耐磨性. 相似文献
2.
3.
研究了一种新型合金溜槽堆焊焊条,用堆焊的方法修复已经磨损的溜槽以及在低碳钢槽体表面堆焊耐磨层。制造出新型高耐磨性的合金槽体。经反复试验筑得了较为理想的焊条药皮配方,所设计的新焊条不但具有较佳的工艺性能。而且堆焊层中合金元素的含量达到了设计要求,试验结果表明,在冲蚀磨损和磨料磨损的条件下,堆焊层具有良好的耐磨性能。 相似文献
4.
5.
针对φ4.0 mm的双熔敷极耐磨堆焊焊条电弧焊中焊条参数与焊接工艺参数对焊接稳定性的影响进行了研究.结果表明,双熔敷极耐磨堆焊焊条电弧焊电弧电压主要由焊条的双芯间距决定,并受到熔滴过渡、电弧吹力等因素的影响,双芯间距太小或者太大都不利于焊接稳定,当双芯间距为1.0mm时,电弧电压为33 V左右,焊接稳定性优良;药皮重量系数为45%~ 56%时,保护效果较好,冶金反应充分,焊接稳定,熔覆层硬度HHRc>6 200 MPa;焊接电流选择180~200 A为宜,这比传统同规格耐磨堆焊焊条焊接电流大且可调范围窄;焊条与工件间的距离为7 mm时,焊接稳定性较好,焊缝与母材熔合良好. 相似文献
6.
Pulsed electrode surfacing of steel with TiC coating: Microstructure and wear properties 总被引:3,自引:0,他引:3
In the present study, pulse electrode surfacing (PES) technique was employed to deposit ultrahard and wear-resistant titanium
carbide (TiC) coating on AISI 1018 steel. Wear resistance of the coated surface increased significantly. An attempt was made
to correlate the thermodynamic predictions and experimental observations. A composite coating that is adherent, crack free,
and defect free in nature was obtained, with TiC being the most stable phase. Islands of TiC of various shapes and sizes are
present in the Fe-rich matrix in the coating. Microhardness measurements suggest high hardness values in the coating region.
Tribological properties such as wear resistance and coefficient of friction were also measured. The coefficient of friction
data do not show significant fluctuations. Wear and friction phenomena in such a coating have been explained on the basis
of a model based on composite/multiphase material. 相似文献
7.
8.
采用碳弧堆焊设备制备 Cr-B-Ni-V 系耐磨合金,在制备过程中加入直流横向磁场.外加磁场将与电弧、熔池相互作用形成电磁搅拌现象,细化堆焊层金属的组织,影响硬质相的形核及分布,进而提高堆焊层的综合力学性能.通过对堆焊层进行硬度、磨损试验以及显微组织分析,研究堆焊速度、磁场强度对堆焊层金属的硬度和耐磨性的影响规律.结果表明,堆焊速度应与磁场电流配合使用,才能使堆焊层的性能得到充分改善;当堆焊速度为 12cm/min,磁场电流为 3A 时,堆焊层的硬度得到最大值,而磨损量达到最小值,其具体数值硬度为 54.4 HRC,磨损量为 0.0335 g.Abstract: In order to refine the structure of deposited metal and control the morphology and distribution of hard phase in surfacing deposit, DC transverse magnetic field was applied to the carbon arc surfacing of Cr-B-Ni-V iron based alloy system. The influence of magnetic intensity and surfacing speed on degree of hardness and wearing resistance was studied through analyzing the hardness, wearing and microstructures of the surfacing deposit. The results show that good match of magnetic field intensity and surfacing speed can improve the properties of surfacing deposit; the optimal values of surfacing deposit are 54.4 HRC and Δm = 0.033 5 when magnetic field current is 3 A, surfacing current is 180 A and surfacing speed is 12 cm/min. 相似文献
9.
10.
The results of investigation of the conditions of formation of macroheterogeneous compositions, deposited with a compound strip electrode, are presented. Mathematical modelling and experiments were carried out to examine the effect of the gap between the main and side strips on the formation of the weld pool, the conditions of formation of the dissimilar composition in the structure and the distribution of hardness within the limits of the single bead. High impact toughness was found in the deposited multilayer compositions with the alternation of the areas of high strength and high ductility within the limits of each layer and with the displacement from layer to layer. 相似文献
11.
试验中在E5515—G型低合金钢焊条药皮中过渡了不同含量的稀土氧化铈,目的是提高焊条性能.采用的试验有焊接接头冲击韧度试验,焊缝金属金相组织试验,X射线荧光光谱试验.结果表明,加入适量的氧化铈能够对焊缝进行脱硫、脱磷,提高熔敷金属的冲击吸收功.氧化铈的加入量不同,脱硫效果不同,且差异较大,而脱磷效果并不十分明显.药皮中加入氧化铈可以细化焊缝组织,但氧化铈的加入量应适当.当氧化铈加入量为3%时,焊缝的组织最细小.当氧化铈加入量最佳时,焊缝金属硫的减少量可达58.13%,而磷的减少量为14.29%. 相似文献
12.
13.
对低碳钢表面进行等离子弧堆焊时外加间歇交变纵向磁场,研究了电磁搅拌对堆焊层金属组织及性能的影响,并利用光学金相、X射线衍射、显微硬度和湿砂橡胶轮磨损试验等手段对试样进行测试分析.研究发现,随着磁场参数的增强,堆焊层中硬质相的数目随之增加,且均匀分布于堆焊层的表面,堆焊层金属的耐磨性也随之增强;当磁场电流为3 A,磁场频率为10Hz时,堆焊层金属的性能达到最佳状态.结果表明,在适当的电磁参数作用下,堆焊层金属才能获得最佳的细化效果;而且电磁搅拌可以控制堆焊层表面中硬质相的形态,使其由长条状和六方块状的混合形态逐渐转变为较规则、均匀的六方块状,从而进一步提高堆焊层金属的硬度和耐磨性. 相似文献
14.
基于Ni-Cr-Mo-V合金体系,研究了稀土氧化钇对800 MPa高强度钢焊条焊缝微观组织和性能的影响.结果表明,Y2O3含量在0~0.02%范围内变化时,随着Y2O3含量的增加,焊缝熔敷金属组织中先共析铁素体逐渐降低,针状铁素体含量逐渐增加,强度和低温冲击韧性均逐渐增加,且当Y2O3含量为0.02%时,焊缝熔敷金属低温冲击韧性达到最大值;当Y2O3含量超过0.02%时,焊缝熔敷金属组织中针状铁素体含量下降,低温冲击韧性降低.综合考虑上述因素,该高强度钢焊条中Y2O3最佳添加量为0.02%左右. 相似文献
15.
16.
双电极石墨型堆焊焊条及单弧焊工艺研究 总被引:1,自引:0,他引:1
介绍了双电极焊条单弧焊工艺,研究了双电极石墨型堆焊焊条。由于石墨型焊条药皮中含有大量的石墨与合金元素,焊条药皮具有导电性,在对石墨型双电极焊条施加电压时,焊条易被击穿。因此,重点研究了双电极之间电阻及焊芯间距对双电极焊条电弧形态、电弧电压及对焊缝成形的影响。试验采用云母片作绝缘剂,用水玻璃粘接。试验结果表明,对于药皮重量系数为58.7%的2×4mm石墨型双电极焊条,在两芯间距为1.4~1.7mm,焊接电流为180~220A的工艺条件下进行焊接,焊缝成形、力学性能较好。 相似文献
17.
18.
19.
Effects of yttrium on microstructure and mechanical properties of Mg-Zn-Cu-Zr alloys 总被引:1,自引:0,他引:1
The effects of yttrium addition on microstructure and mechanical properties of as-cast Mg-6Zn-3Cu-0.6Zr-xY(x=0,0.5, 1.0,1.5 and 2.0,mass fraction,%)(ZCK630+xY for short in this study)alloys were investigated by means of OM,XRD and SEM. The results show that the average grain size of Mg-Zn-Cu-Zr magnesium alloy is effectively reduced(from 57μm to 39μm)by Y addition.The analysis of XRD indicates the existence of I-phase(Mg3Zn6Y)and W-phase(Mg3Zn3Y2)in ZCK630 alloys with Y addition.The ultimate tensile strength of ZCK630 alloys is significantly deteriorated with increasing Y addition,which is possibly related to the continuous networks of intergranular phases and the increase of W-phase. 相似文献
20.
Experimental results show that exothermic reactions in the stage of heating and melting of an electrode coating take place when the content of the exothermic mixture in the coating is higher than 35%. The results of investigations of the content of the exothermic mixture in the electrode coating on the melting parameters are presented. 相似文献