共查询到19条相似文献,搜索用时 812 毫秒
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氮碳合金化自保护硬面药芯焊丝堆焊层的组织与性能 总被引:1,自引:0,他引:1
研制出了氮碳合金化自保护硬面药芯焊丝,探讨了回火温度对氮碳合金化自保护硬面药芯焊丝堆焊层硬度和耐磨性能的影响.结果表明:其堆焊层硬度为36.5~45.5 HRC,显微组织为板条马氏体和铬、钛、钒、铌的氮碳化物的复合物,堆焊层中的氮碳化物质点不易分解,有良好的稳定性和抗高温回火性能;回火温度为550 ℃时,堆焊层硬度达到最大值,回火温度高于550 ℃,硬度值基本保持不变;氮碳合金化自保护硬面药芯焊丝堆焊层金属的磨损机理为磨粒切削后塑性磨痕和氮碳化物的块状剥离,堆焊层具有良好耐磨性能的最佳回火温度为480~520 ℃. 相似文献
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Cr5系堆焊合金碳、铬过渡形式对高温磨损性能影响的研究 总被引:1,自引:0,他引:1
在轧辊堆焊复合制造中,为节约贵重碳化物及提高堆焊材料的性价比,在堆焊熔敷金属成分基本保持不变的条件下,利用埋弧堆焊研究药芯焊丝碳、铬不同加入方式对堆焊合金微观组织与性能的影响。通过磨损试样前后硬度、高温拉伸、常温韧性与高温磨损量的量化,结合磨损前后金相组织、扫描电镜等辅助手段分析微观组织、加入方式与耐磨性之间的关系;结果表明:堆焊金属600℃的高温耐磨性能与合金高温强度及硬度呈正比,并随合金韧性的增加耐磨性能提高;直接加石墨和铬粉的药芯焊丝堆焊熔敷金属的耐磨性能优于在焊丝中直接加碳化铬的堆焊熔敷金属。高温磨损是合金氧化、切削、疲劳开裂与剥离等多种因素作用的结果,理想的高温耐磨堆焊材料不仅与采用的堆焊合金系有关,还与堆焊金属的显微组织、抗氧化性能及高温强韧性等因素有关。同时得出改变合金的加入方式是不添加变质剂及外加激振法外,能够促使组织均匀及强化熔敷金属的另一种方式。 相似文献
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利用药芯焊丝对已磨损的K360耐磨钢进行CO2气体保护堆焊修复,并采用不同硬度的23MnNiMoCr54高强钢与堆焊层配副进行对磨试验。结果表明,随着对磨材料硬度的提高,摩擦副的摩擦系数变化较小,磨损量逐渐变小,磨损面较光滑,其磨损机理主要为显微切削。由于堆焊层对不同硬度的对磨材料都造成了较严重的磨损,因此其不适合作为K360耐磨钢的堆焊修复材料。 相似文献
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对国产药芯焊丝YJS07和YJS02进行了焊接工艺试验,观察了药芯焊丝熔敷金属的显微组织,分析了药芯焊丝的熔敷金属化学成分。进行了药芯焊丝所焊焊接接头的低温冲击试验及焊接接头的常温拉伸试验。结果表明,国产药芯焊丝YJS07和YJS02具有良好的焊接工艺性能,其熔敷金属扩散氢含量较低;YJ507药芯焊丝的熔敷金属中含有一定量的镍,细化了先共析铁素体,提高了其低温韧性;YJS02药芯焊丝的熔敷金属含有一定量的钛和硼,易于形成针状铁素体,从而提高其低温韧性。 相似文献
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The effects of welding processes on abrasive wear resistance for hardfacing deposits 总被引:1,自引:0,他引:1
In this research, four kinds of welding deposits were evaluated, applied through two different welding processes: flux cored arc welding (FCAW) and shielded metal arc welding (SMAW). The other variable of the tests was the deposited layers. The hardfacing deposits were evaluated using the dry sand-rubber wheel machine according to procedure A of the ASTM G65 standard. Optical and scanning electron microscopy was used for the characterization of the microstructure and worn surface of deposits. FCAW welds presented higher abrasive wear resistance than the SMAW deposits. The hardfacing deposit formed by uniformly distributed carbides rich in titanium presented the highest abrasive wear resistance. Abrasive wear resistance was higher when three layers were applied, except for SMAW-D deposit. It was not possible to get a clear relation between hardness and the abrasive wear resistance of the deposits. The results showed that the most important variable to improve abrasion resistance is the microstructure of hardfacing deposits, where the carbides act as barriers to abrasive particle cutting. 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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In order to improve the wear resistance of Fe-Cr-C hardfacing alloy, titanium carbonitride was introduced in situ and a TiC-Tix(C,N)y coating was deposited on the surface of ASTM G3101 steel by a gas metal arc welding process. The microstructure and wear resistance of the hardfacing layer were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS), macroscopic hardness meter, spectrometry, and transmission electron microscopy (TEM). The results show that the hardfacing layers mainly consist of (Cr,Fe)7C3, TiC carbides, Tix(C,N)y carbonitrides, and α-Fe (C0.14Fe1.86 and C0.12Fe1.88 martensite) (BCT) in addition to a low content of retained CFe15.1 austenite (FCC). The titanium carbonitride–reinforced coating has high hardness and excellent wear resistance under dry sliding wear test conditions. 相似文献
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The abrasion wear resistance of Fe–32Cr–4.5C wt% hardfacing alloy was investigated as a function of matrix microstructure.
In this study, the alloy was deposited on ASTM A36 carbon steel plates by the shielded metal arc welding (SMAW) process and
the as-welded matrix microstructure was changed into ferrite, martensite, and tempered martensite by heat treatment processes.
The Pin-on-disk test results show that under low (5 N) and high (20 N) load conditions, the wear resistance behavior of the
as-welded matrix sample is 20 and 15% higher, respectively, than the martensitic matrix sample, although the bulk hardness
of the as-welded matrix is 5% lower. The ferritic matrix sample has the poorest wear resistance behavior which is less than
half of that of the as-welded matrix one. Micro-ploughing, micro-cutting, and micro-cracking are recognized as the micro-mechanisms
in the material removal in which the proportion of micro-ploughing mechanism increased by increasing matrix toughness. 相似文献
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A series of high carbon Fe–Cr–C hardfacing alloys were produced by gas tungsten arc welding (GTAW). Chromium and graphite alloy fillers were used to deposit hardfacing alloys on ASTM A36 steel substrates. Depending on the four different graphite additions in these alloy fillers, this research produced hypereutectic microstructures of Fe–Cr phase and (Cr,Fe)7C3 carbides on hard-facing alloys. The microstructural results indicated that primary (Cr,Fe)7C3 carbides and eutectic colonies of [Cr–Fe+(Cr,Fe)7C3] existed in hardfacing alloys. With increasing the C contents of the hardfacing alloys, the fraction of primary (Cr,Fe)7C3 carbides increased and their size decreased. The hardness of hardfacing alloys increased with fraction of primary (Cr.Fe)7C3 carbides. Regarding the abrasive characteristics, the wear resistance of hardfacing alloys were related to the fraction of primary (Cr,Fe)7C3 carbides. The wear mechanism was also dominated by the fraction of primary (Cr,Fe)7C3 carbides. Fewer primary carbides resulted in continuous scratches worn on the surface of hardfacing alloy. In addition, the formation of craters resulted from the fracture of carbides. However, the scratches became discontinuous with increasing fraction of the carbides. More primary carbides can effectively prevent the eutectic colonies from the damage of abrasive particles. 相似文献
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TiC-VC颗粒增强Fe基熔敷层组织与耐磨性能 总被引:9,自引:0,他引:9
以H08A为焊芯,以钛铁、钒铁和石墨等为药皮组分,利用焊接电弧高温冶金反应,在Q235基体上制备TiC-VC复合超硬颗粒增强Fe基熔敷层。利用扫描电镜、X射线衍射仪、透射电镜、能谱分析仪及磨损试验,研究了熔敷层的组织、性能及组分加入量对熔敷层性能的影响。研究结果表明:冶金反应形成的TiC-VC颗粒尺寸细小,且弥散分布在基体上;熔敷层硬度在HRC55以上,具有很高的耐磨性和良好的抗裂性;钛铁、钒铁及石墨加入量(质量分数)分别为15%~18%、12%~14%和8%~10%时,熔敷层具有良好的耐磨性能和抗裂性能。 相似文献
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Reinforcing a temperature resistant matrix with carbides (MMC, metal matrix composite) is expected to improve the abrasion
resistance at high temperatures. Experiments show that carbides brought in during a plasma transferred arc (PTA) welding process
get partly dissolved in the martensitic matrix and secondary carbide structures precipitate. Further analyses with nano-indentation
and XRD show that these secondary precipitations strongly influence the properties of the originally homogeneous ductile martensitic
matrix. Although hot hardness is increased, wear resistance is diminished due to changed nano-microstructural material properties. 相似文献