冷热循环对多元合金铁基堆焊层硬度的影响

研究了热循环温度和循环次数对多元合金铁基堆焊层硬度的影响.结果表明:冷热循环对多元合金铁基堆焊层硬度有较大的影响,当其经560℃(=)18℃冷热循环超过100次后,堆焊层硬度为56.3HRC;经700℃(=)18℃冷热循环120次后,堆焊层硬度为42.5HRC,该堆焊层具有较高的抗急冷急热软化能力.     

堆焊

45CrNiMOVA钢堆焊修复层组织及摩擦学性能;K360耐磨钢堆焊合金层的组织与性能;冷热循环对多元合金铁基堆焊层硬度的影响;锡青铜堆焊工艺;脉冲磁场电流对堆焊金属组织及性能的影响     

堆焊

45CrNiMOVA钢堆焊修复层组织及摩擦学性能；K360耐磨钢堆焊合金层的组织与性能；冷热循环对多元合金铁基堆焊层硬度的影响；锡青铜堆焊工艺；脉冲磁场电流对堆焊金属组织及性能的影响     

手弧堆焊Fe3Al堆焊层的组织形貌与抗氧化性能

通过将Fe3Al合金制成焊条,使用手弧堆焊（MAS）的方法,成功地在不锈钢基体上堆焊了Fe3Al堆焊层,并研究了Fe3Al合金的堆焊工艺、堆焊层的组织形貌及高温抗氧化性能,研究发现,由于Fe3Al合金本身的固有脆性,若不采用合适的热处理工艺时,堆焊层易开裂,当采用500℃预热基体,堆焊后700℃退火处理,则可得到无裂纹的Fe3Al堆焊层。堆焊层的Al含量在堆焊过程中损失较大,但不影响堆焊层的抗氧化性能。在静态空气炉中经800℃/70h氧化试验后,不锈钢基体氧化十分严重,而Fe3Al堆焊层氧化很轻微,显现出极好的抗氧化性能。     

碳化钨应用于强力磨料磨损件的堆焊研究

用珠光体作为底层,以高铬锰奥氏体作为过渡层进行碳化钨的电弧堆焊,能够很好地解决堆焊材料与基体金属的相容性问题.对碳化钨材料的抗磨损性能及其焊接工艺性进行了分析,认为碳化钨在抗强力磨损的大型零件上采用电弧堆焊不失为一种好的方法,并介绍了使用该方法在水泥辊压机辊面堆焊中的实践验证情况.     

一种Cr-W-Mo-Mn-V铁基堆焊层的力学与耐磨性能

通过试验考察了一种Cr-W-Mo-Mn-V铁基堆焊层经不同温度回火后的硬度变化,并测试了该堆焊层经500℃回火前后的冲击性能和耐磨性.结果表明,该堆焊层焊态具有较高的回火稳定性,经500℃保温2h回火后,堆焊层的硬度达49.5HRC,其冲击韧度和耐磨性较焊态分别提高了7.98%和11.43%.     

大型热轧定宽压力机出钢辊的堆焊复合

针对出钢辊长期在温度800℃以上、红热钢坯作用下产生严重的冷热疲劳龟裂和金属间磨损的现象,开发出采用N合金化的堆焊硬面药芯焊丝材料。其显微组织为马氏体+少量铁素体+合金化合物,堆焊层金属具有极高的抗高温软化性能、抗冷热疲劳性能和耐金属磨损性能。制定了合理的堆焊工艺规范,堆焊复合制造的出钢辊使用寿命可长达半年,无热疲劳裂纹的产生,金属间磨损小,满足使用要求。     

超高锰钢锤头的复合堆焊修复研究

在分析超高锰钢锤头的破坏行为和磨损机理后，采用“母材 中间过渡层 耐磨层”的复合堆焊工艺进行了超高锰钢锤头的堆焊修复试验，并分析了不同焊条堆焊的过渡层和焊接热影响区的组织结构。应用新研制的GMl焊条堆焊过渡层成功地堆焊修复了超高锰钢锤头。工业应用结果表明，这种复合堆焊修复的超高锰钢锤头具有极好的抗磨损性能，使锤头的使用寿命提高了2．5—3倍。     

连铸辊堆焊用药芯焊带的研究

通过药芯焊带的成分设计，筛选，堆焊层各项性能试验（如堆焊层硬度耐高温氧化性，耐冷热疲劳性试验及产品堆焊试验）研制出用于连铸埋弧自动堆焊的ＤＬ－１１型药芯焊带。     

双钨极堆焊技术在核反应堆压力容器制造中的应用与研究

按照核反应堆压力容器不锈钢堆焊工艺评定,分别堆焊了单钨极与双钨极不锈钢堆焊层,通过对比分析两者的焊缝成形、金相组织、硬度分布、化学成分、冲击性能、晶间腐蚀等,说明双钨极与单钨极的主要区别。结果表明,双钨极与单钨极堆焊均能获得良好的焊缝成形,但双钨极焊接效率较单钨极有大幅提升。双钨极与单钨极焊缝其金相组织、硬度分布、冲击性能和晶间腐蚀性能等较为接近。该技术已开始应用于反应堆压力容器的制造。     

镁合金微弧氧化涂层的摩擦学性能研究

利用扫描电镜分析了AZ91D镁合金微弧氧化膜的组织形貌,对氧化膜硬度及摩擦学行为进行了研究。结果表明:微弧氧化膜能显著提高镁合金基体的硬度和抗磨性能,但其摩擦系数较镁合金基体高。涂层厚度对涂层的减摩性能影响较小,但对其抗磨性能影响较大,并存在提高抗磨性能的最佳涂层厚度。涂层的磨损机制主要是磨粒磨损和剥层磨损。     

冷喷涂制备CuZn35涂层结构及耐摩擦磨损性能

目的 采用高压冷喷涂技术制备低氧化、致密、耐摩擦磨损的CuZn35涂层,并探究加速气体温度对CuZn35涂层性能的影响。方法 利用高压冷喷涂技术在铝板上沉积CuZn35涂层,探究加速气体温度对冷喷涂CuZn35涂层微观结构及耐摩擦磨损性能的影响。在载荷为2 N时,在旋转式摩擦磨损试验仪上进行试验,对比铸态CuZn35材料的耐磨性能,评估在压力为5 MPa,加速气体温度为400、600、800℃条件下冷喷涂制备的CuZn35涂层的耐磨性能。通过光学显微镜(OM)、扫描电镜(SEM)、三维轮廓仪(3D Profiler)对涂层的微观结构和磨损表面形貌进行分析。结果 当冷喷涂加速气体温度从400℃升至800℃时,CuZn35涂层内部颗粒的变形量不断增大,颗粒之间形成了较好的结合,孔隙率从2.67%降至0.5%以下,硬度从200HV0.3升至242HV0.3,涂层磨损率从3.67 mm³/(N·mm)降至1.80 mm³/(N·mm)。在温度为800℃条件下制备的CuZn35涂层表现出最优的耐摩擦磨损性能,在磨损过程中涂层材料未发生明显的块状脱落现象...     

电刷镀在表面工程中应用的研究进展

综述了电刷镀技术在材料表面防腐、耐磨及维修领域的应用。 介绍了电刷镀耐蚀、耐磨镀层的新工艺及其性能,包括纳米晶合金电刷镀层、纳米复合电刷镀层、双纳米复合电刷镀层以及电刷镀复合转化膜层的研究现状。 最后指出了今后电刷镀技术研究应用的方向。     

激光熔覆 CBN 膜层的形态特征及性能研究

目的提高钛合金的表面硬度和耐磨性能。方法采用激光熔覆工艺,在TC11钛合金表面制备80%CBN+20%Ti(均为质量分数)熔覆层,分析熔覆层的显微组织、硬度和耐磨性能。结果熔覆层的显微组织沿层深方向分为熔覆区、结合区和过渡区三个区域,区域之间没有明显的裂纹和断层。CBN膜层的显微硬度最高达到950HV0.2,耐磨性比纯Ti熔覆层提高了近14倍。结论在钛合金表面激光熔覆CBN抗磨涂层,不仅耐磨损性能良好,而且表面硬度得到了有效提高。     

Microstructure and oxidation of multi-layer MoSi2-CrSi2-Si coatings for SiC coated carbon/carbon composites

Multi-layer MoSi₂-CrSi₂-Si anti-oxidation coatings with different compositional ratios were prepared on the surface of SiC coated carbon/carbon (C/C) composites by a two-step pack cementation method. The microstructure and anti-oxidation performance of the coating were studied. The results show that the multi-layered coatings could protect the C/C composites from oxidation in air at 1773 K for 1000 h or 1873 K for 750 h, respectively. The anti-oxidation performance of the multi-layer MoSi₂-CrSi₂-Si coating is mainly attributed to their dense and microcrack-free structure, appropriate thermal expansion coefficient and the well dispersed MoSi₂ and CrSi₂ in the coating.     

钢坯高温抗氧化涂料应用效果试验研究

由于钢坯在加热过程中温度高、时间长,其表面氧化烧损严重,不仅降低了热连轧过程金属收得率,而且影响轧制过程中高压水的除鳞效果,产生带钢表面质量缺陷,为此出现了高温抗氧化涂料的研究和应用。在某常规热连轧生产线针对低碳钢、微合金钢、耐侯钢,试验研究了一种钢坯高温抗氧化涂料的高温防氧化效果及使用性能。结果表明,试验应用的高温抗氧化涂料具有较好的高温防护效果,实现了加热过程板坯表面氧化铁皮厚度的有效减薄,其中,低碳钢平均减薄46.25%,微合金钢平均减薄24.38%,耐候钢平均减薄18.90%,且涂料与钢坯基体剥离效果良好,对轧后带钢的表面质量无影响。     

Structure and sliding wear behavior of 321 stainless steel/Al composite coating deposited by high velocity arc spraying technique

A typical 321 stainless steel/aluminum composite coating （321/Al coating） was prepared by high velocity arc spraying technique （HVAS） with 321 stainless steel wire as the anode and aluminum wire as the cathode. The traditional 321 stainless steel coating was also prepared for comparison. Tribological properties of the coatings were evaluated with the ring-block wear tester under different conditions. The structure and worn surface of the coatings were analyzed by scanning electron microscopy（SEM）, X-ray diffractometry（XRD） and energy dispersion spectroscopy（EDS）. The results show that, except for aluminum phase addition in the 32 l/Al coating, no other phases are created compared with the 321 coating. However, due to the addition of aluminum, the 32 l/Al coating forms a type of ＂ductile/hard phases inter-deposited＂ structure and performs quite different tribological behavior. Under the dry sliding condition, the anti-wear property of 32 l/Al coating is about 42% lower than that of 321 coating. But under the oil lubricated conditions with or without 32 h oil-dipping pretreatment, the anti-wear property of 321/AI coating is about 9% and 5% higher than that of 321 coating, respectively. The anti-wear mechanism of the composite coating is mainly relevant to the decrease of oxide impurities and the strengthening action resulted from the ＂ductile/hard phases inter-deposited＂ coating structure.     

Anti-oxidation properties of ZrB2 modified silicon-based multilayer coating for carbon/carbon composites at high temperatures

To improve the anti-oxidation ability of silicon-based coating for carbon/carbon (C/C) composites at high temperatures, a ZrB₂ modified silicon-based multilayer oxidation protective coating was prepared by pack cementation. The phase composition, microstructure and oxidation resistance at 1773, 1873 and 1953 K in air were investigated. The prepared coating exhibits dense structure and good oxidation protective ability. Due to the formation of stable ZrSiO₄–SiO₂ compound, the coating can effectively protect C/C composites from oxidation at 1773 K for more than 550 h. The anti-oxidation performance decreases with the increase of oxidation temperature. The mass loss of coated sample is 2.44% after oxidation at 1953 K for 50 h, which is attributed to the decomposition of ZrSiO₄ and the volatilization of SiO₂ protection layer.     

Corrosion resistance and mechanical properties of pulse electrodeposited Ni–TiO2 composite coating for sintered NdFeB magnet

Ni–TiO₂ composite coating which was prepared under pulse current conditions was successfully performed on sintered NdFeB magnet. As a comparison, pure nickel coating was also prepared. The phase structure, the surface morphology, the chemical composition, the anti-corrosion performance of the coatings for magnets, the microhardness and the wearing resistance performance of the coatings were studied using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), electrochemical technique, Vickers hardness tester and ball-on-disc tribometer, respectively. The results revealed that Ni–TiO₂ composite coating provided excellent anti-corrosion performance for the magnets, and showed higher microhardness and better anti-wear performance.     

电泳-电沉积 Ni-金刚石复合镀层及其耐磨性能研究

先采用电泳技术在铜基体表面沉积均匀、致密的金刚石微粒,再将已覆盖有金刚石微粒的基体放入电镀液中进行电沉积金属镍,获得了金刚石质量分数约为48%且分布均匀的Ni-金刚石复合镀层。与纯镍镀层进行磨损试验对比,发现制备的Ni-金刚石复合镀层磨痕较浅,磨损量较小,其对磨件的磨损体积约为纯镍镀层对磨件的17倍,表明此两步沉积工艺制备的复合镀层具有良好的耐磨性能。