φ5.8mm钼杆焊接质量分析

以焊接法生产大单重钼丝的工艺过程为研究对象,简要介绍了加压接触焊接方法的工作原理。着重分析了1 kg的φ17 mm钼棒采用203旋锻开坯、经串打至φ5.8 mm、焊接后焊接部位的质量。通过分析焊接部位的抗拉强度、断口金相组织、SEM形貌以及杂质分布等,并与相同钼杆的正常断口进行比较,最终对焊接钼杆的质量作出评价。     

φ5.8mm钼杆焊接质量分析

以焊接法生产大单重钼丝的工艺过程为研究对象,简要介绍了加压接触焊接方法的工作原理.着重分析了1 kg的φ17 mm钼棒采用203旋锻开坯、经串打至φ5.8 mm、焊接后焊接部位的质量.通过分析焊接部位的抗拉强度、断口金相组织、SEM形貌以及杂质分布等,并与相同钼杆的正常断口进行比较,最终对焊接钼杆的质量作出评价.     

镧钼合金在电火花切割加工中的应用研究

进行了镧钼丝与纯钼丝作电火花切割电极丝的对比试验，试验结果显示；在合理控制镧钼丝加工工艺的条件下，镧钼丝具有较高的抗拉强度和高温强度，其线切割使用寿命明显高于纯钼丝，试验数据显示提高50%左右，实践表明，在电火花线切割加工行业，用镧钼丝代替纯钼丝作电极丝，可有效降低切割成本，极具推广应用价值。     

钴对钼丝加工及组织性能的影响

研究了钴对钼丝的拉伸性能及其加工硬化的影响。对加工态和退火态纯钼丝及掺杂结构钼丝的金相组织、力学性能进行观察和分析,发现钼中加钴提高了钼丝的加工硬化率,降低了再结晶温度,并且明显改善了退火钼丝的室温延性。因此,掺钴钼丝是一种性能优良的丝材。     

微掺镧钼丝组织和性能

系统地研究了纯钼丝、微掺镧钼丝在不同温度下退火后的组织和性能。结果表明，微掺镧显著地改善了钼丝的强韧性能，提高了钼丝的室温强度和再结晶温度，改善了丝材再结晶后的室温脆性。微掺镧钼丝综合性能明显高于纯钼丝。     

钼及钼合金焊接技术研究现状及进展

本文系统总结了钼及钼合金焊接技术的研究现状和最新进展,分别介绍了近年来电子束焊、钨极氩弧焊、激光焊、电阻焊、钎焊和摩擦焊等6种焊接技术应用于钼及钼合金焊接所取得的进展和发现的问题,论述了各种焊接技术的特点,结合钼合金焊接性特点对各种焊接技术应用于钼及钼合金焊接的发展前景进行了分析和展望。     

钼丝断裂行为研究

通过对钼丝生产过程中出现的断口实物样分析，阐明造成钼丝断裂的原因，提出钼丝生产用金属钼棒及其拉拔生产的关键工艺参数控制原理，达到降低钼丝断裂几率，提高综合成材率的目的。     

多元复合稀土钼材的研究

介绍了通过粉末冶金方法在钼中掺杂１种稀土氧化物（简称单元稀土）和掺杂３种稀土氧化物（简称多元复合稀土）制取钼材的工艺要点,并对掺杂钼粉、坯条及不同温度退火丝材的性能和组织进行了研究。结果表明：多元复合稀土钼丝的生产工艺与纯钼丝生产工艺基本相同;多元复合稀土同单元稀土一样,都能大大提高钼丝的强度;多元复合稀土钼丝与同含量的单元稀土钼丝相比,多元复合稀土钼丝表现出优异的高温退火强度,具有更高的延伸率和可加工性。     

掺杂钼丝的组织与性能

系统地研究了纯钼丝、高温钼丝和镧钼丝在不同温度下进行热处理后的组织与性能。结果表明,掺杂提高了丝材的室温强度和再结晶温度,改善了再结晶后的室温脆性,综合性能明显高于纯钼丝。     

钼丝热阻性能的测量

(一)钼丝室温电阻稳定方法 钼丝加热前较加热后室温电阻(R_0)大。为了使室温电阻稳定,对钼丝进行了热处理即:对钼丝反复加热,待冷却之后,用电桥     

Sintering of molybdenum pressing in moist hydrogen and their rolling into strip

Conclusions A method has been developed and introduced into production for the preparation of molybdenum powders and the sintering of plates from them suitable for rolling without the use of high-temperature welding in a welding apparatus. The method has been used to produce molybdenum sheets in squares from 100×100 to 180×180 and thickness from 1 to 3 mm in amounts of 5–6 t per year.     

有机钼研究与开发现状

综述了国内外有机钼研究与开发现状。并重点评述了有机钼在润滑剂、添加剂、催化剂、粘结剂、热加工和气体保护焊接等方面的应用前景．     

Diffusion welding of heaters made of molybdenum disilicide

Conclusions It has been established that with diffusion welding in a vacuum and under optimal conditions, a physical interface is completely absent between the welded materials, i.e., the structure of the welding zone does not differ from the structure of the starting molybdenum disilicide. The porosity is 2.1%. The size of the pores varies from 2 to 70, and the zone of the welded bond of molybdenum disilicide is equal in strength to the base material.Tests under industrial conditions showed that the molybdenum disilicide heater, welded by diffusion welding in a vacuum, worked on a par with those imported, and lasted 3000 h at a temperature of 1650–1700°C.As a result of developing and introducing the new technology of producing molybdenum disilicide heating rods, the Moscow Hard Alloys Combine has obtained a great economic saving, of the order of 350,000 rubles in 1961–1962.     

焊缝掺杂对工业纯钼可焊性的影响

叙述了三种纯钼（粉末冶金，低碳弧铸和高碳弧铸纯相）在气体保护钨弧焊之前，用射频溅射法沉积到焊接件缝处的钛和铪掺杂剂对焊缝的若干有利影响；（１）减少粉末冶金纯钼焊接件的焊缝中形成的中心线裂纹和孔洞，（２）硬化焊接熔融区；（３）减少所有不同种类型纯钼的焊接熔融区中的晶间破坏趋势，同时简单讨论了掺杂剂改革焊接质量和断裂的机理。     

Vacuum diffusion welding of metalline carbides to high-melting metals

Conclusions The conditions of vacuum diffusion welding of zirconium, niobium, and tantalum carbides to the following high-melting metals: niobium, tantalum, molybdenum, and tungsten were investigated. Microstructural investigations of the weld seams were performed. The nature of the new phases that developed as a result of reaction diffusion was investigated by using the microhardness method, and assumptions concerning the mechanism of phase formation were made.     

Mass Transfer and Weld Appearance of 316L Stainless Steel Covered Electrode During Shielded Metal Arc Welding

The mass transfer and the weld appearance of 316L stainless steel covered electrodes during shielded metal arc welding were investigated. According to the experimental measurements on the deposited metal and the observations on the welding process, the mass transfer coefficient of the nickel was found to be in the range of 88.09 to 99.41 pct, while those of molybdenum, chromium, manganese, and silicon are in the ranges of 84.60 to 92.51 pct, 71.59 to 77.64 pct, 20.88 to 30.15 pct, and 6.72 to 10.47 pct, respectively. Some relationships between the mass transfer and the flux coating ingredient/welding current were established. The formability properties of the weld, including the spreadability, spattering, slag detachability, and oxidation tint on the weld surface, were also discussed based on the tested data and the observations.     

Optimal concentration of nanostructured powder in protective gas

In the present work, a method is developed for determining the optimal concentration of nanostructured powder in the protective gas in welding by a floating electrode in argon. The theoretical analysis is confirmed by experiments with molybdenum nanopowder, which is introduced in the welding bath through a special device. The apparatus used for surfacing of the sample includes a GSP-2 welding head combined with the specially developed device and a VS-300B power source. In surfacing 12Kh18N10T steel samples, 12Kh18N19T steel welding wire (diameter 1.2 mm) is employed. To ensure a satisfactory weld joint, the dendrite dimensions must be minimized. Stable welding is ensured by transfer of a droplet of electrode metal from the end of the welding wire to the welding bath. Hence, the droplet volume must also be minimized. Before optimizing the concentration of nanostructured powder in the protective gas, the influence of the welding parameters on the microstructure of the surfaced metal is established. The results show that the grain size is smallest with a current of 240–260 A and an arc voltage of 28–30 V. In those conditions, the optimal concentration of nanostructured powder in the protective gas is determined. It is found that the optimal concentration is 20 mg per 1 m of weld seam. The use of different concentrations of nanostructured powder in the protective gas results in different microstructure of the applied metal. When the concentration of nanostructured powder in the protective gas is 20 mg per 1 m of weld seam, the branching of the dendrites is least and the dendrite size corresponds to equilibrium structure. On adding nanostructured powder to the liquid bath, the mechanical properties of the weld joints are increased by 7.5% at +20°C and by 6.5% at +500°C.     

Decomposition of ferrite in commercial superduplex stainless steel weld metals; microstructural transformations above 700 °C

The microstructural stability at temperatures above 700 °C of weld metal of type 29Cr-8Ni-2Mo-0.39N and weld metal of type 25Cr-10Ni-4Mo-0.28N has been compared. Multipass welding was employed using the gas tungsten arc welding technique with a shielding gas of Ar+2 pct N₂. The quantitative assessment of the intermetallic phase was performed using automatic image analysis in the light optical microscope (LOM). Detailed microanalysis was also performed using scanning and transmission electron microscopy. A computer program developed by the authors was used to calculate a continuous cooling-temperature (CCT) diagram on the basis of the experimentally determined time-temperature-transformation (TTT) diagram. Thermodynamic calculations for estimating phase stabilities and for interpreting experimental observations were performed. It was found that weld metal of type 29Cr-8Ni-2Mo-0.39N was microstructurally more stable than weld metal of type 25Cr-10Ni-4Mo-0.28N. A lower molybdenum concentration and a higher nitrogen concentration in the former alloy could explain the higher stability with respect to the intermetallic phase. The higher nitrogen concentration also provides a rationale for the higher stability against the formation of secondary austenite in weld metal of type 29Cr-8Ni-2Mo-0.39N. This effect, which is associated with a lower thermodynamic driving force for precipitation of secondary austenite during multipass welding, can be explained by nitrogen-enhanced primary austenite formation.     

德国钼业的创新与发展

德国钼资源匮乏,长期以来依靠进口钼精矿进行深加工生产出钼系列产品,如钼颜料、催化剂、添加剂、钼粉、钼合金和钼溅射靶材等。许多产品已走向世界,德国钼业的创新促进了钼业健康可持续发展。