70钢Φ6.5mm线材控冷工艺实践

对邢钢70钢Ф6．5mm线材的控制冷却工艺进行了对比,当开轧温度为1000-1040℃、终轧温度为920—950℃、吐丝温度为875—905℃时,线材的力学性能达到预期效果,索氏体化率达到90％,满足了用户的要求。     

Modeling and finite element analysis of rod and wire steel rolling process

Two thermomechanical coupled elastic-plastic finite element （FE） models were developed for predicting the 12-pass continuous rolling process of GCrl 5 rod and wire steel. The distances between stands in the proposed models were set according to the actual values, and the billets were shortened in the models to reduce the calculation time. To keep the continuity of simulation, a technique was developed to transfer temperature data between the meshes of different models in terms of nodal parameters by interpolation functions. The different process variables related to the rolling process, such as temperature, total equivalent plastic strain, equivalent plastic strain rate, and contact friction force, were analyzed. Also, the proposed models were applied to analyze the reason for the occurrence of an excessive spread in width. Meanwhile, it was also utilized to assess the influence of the roll diameter change on the simulated results such as temperature and rolling force. The simulated results of temperature are found to agree well with the measured results.     

漆包线弯曲盐水针孔试验法的标准化探讨

本文通过介绍了用漆包线弯曲盐水针孔试验法检验漆包线的漆膜连续性、附着性的理论基础及其应用前景。     

树脂芯助焊剂性能的基础研究

焊锡丝主要应用于仪器、仪表、各种家用电器等的焊接、补焊以及维修,而其焊接质量的好坏不仅取决于焊锡丝的合金材料,更取决于其树脂芯助焊剂的性能,通过大量的实验对影响其性能的因素进行了分析,并对可焊性进行测试,从而制备出诸如卤素含量低,扩展率好等综合性能优良的树脂芯助焊剂.     

18×7类不旋转钢丝绳结构特点

指出18×7类不旋转钢丝绳用途的广泛性,通过对18×7类不旋转钢丝绳结构特点的认识,分析钢丝绳的稳定性及产品缺陷,举例说明提高钢丝绳实物质量的措施和行业内急需解决的技术难题。     

钢丝非稳态加热的运行速度计算

在热处理钢丝时,大多在对流换热条件下对钢丝进行加热,铅浴热处理是其加热方法之一。本文根据传热学理论,依据能量守恒原理,应用集总热容法,对钢丝在第三类边界条件下的加热建立合适的数学模型,推导出第三类边界条件下的钢丝在对流换热情况时的加热时间计算式,给出了钢丝表面到温和钢丝中心到温时间表达式,由此导出钢丝非稳态加热的运行速度计算式,为钢丝热处理工艺的制定和钢丝加热炉(槽)的设计提供理论计算依据。     

Dieless drawing steel wires using a dielectric heating method and modeling the process dynamics

Modern industries require the production of multi-functional, inorganic, micron-sized metal wires. This study suggests a novel method that could potentially offer a highly efficient dieless drawing technology for manufacturing thin stainless steel fibers. The method is based on a hot-working principle, using microwaves as the heat source and SiC as the susceptor. Experimental trials with a laboratory rig showed that the new system worked effectively for drawing the stainless steel wires and should be able to realize the diameter attenuation with a diameter reduction of up to 21%. The theoretical model describing the deformation behavior of the stainless steel wires in the working zone along with the constitutive equation of Bingham model modified with a power law and Zener–Hollomon parameter turned out to match very good with the actual results of the experiment. The coefficient of variation of the drawn wire diameter increased, as the draw ratio increased, which could be attributed to the occurrence of the narrow necking zone.     

提高12Cr2MoWVTiB与12Cr1MoV异种钢焊缝金属冲击韧性的研究

在制造高温、高压锅炉时经常会遇到耐热合金12Cr2MoWVTiB与12Cr1MoV异种钢的焊接,其焊缝金属冲击值不高的问题尤为突出,严重影响了锅炉的安全运行和可靠性,所以如何提高焊缝冲击韧性值的问题显得非常迫切。通过两次选择焊材及试验分析比较后,最终获得了满意的冲击韧性值,为以后焊材选配提供了保障和依据。在Cr-Mo钢焊接时考虑到长时间热处理后会促成铁素体(F)的形成而导致接头韧性下降,所以应谨慎使用含碳量过低的焊材。另外,对于含铬量大于1.25%的低合金钢焊接,最佳预热温度为150℃～200℃,高于250℃时其冲击韧性值会明显下降。     

Experiment study on electroplated diamond wire saw slicing single-crystal silicon

This paper conducted the slicing experiments of single-crystal silicon using a reciprocating electroplated diamond wire saw. The machined wafer topography and wire wear were observed by using scanning electron microscope (SEM). The influences of process parameters and cutting fluids on single-crystal silicon wafer surface roughness (SR), subsurface micro-crack damage (SSD) depth, total thickness variation (TTV) and warp were investigated. The bonded interface sectioning technique was used to examine the cut wafers SSD depth. Study results show that a higher wire speed and lower ingot feed speed can produce lower wafer SR and SSD; the lower warp of wafer needs lower wire speed and ingot feed speed; and low wafer TTV can be obtained by an appropriate matching relationship between wire speed and ingot feed speed. The synthetic cutting fluid has a better total effect to improve the wafer quality. The pulled-out of diamond abrasives is the main wear form of wire, which indicates that more research on improving the abrasives retaining strength on wire surface should be investigated in fixed-abrasive wire manufacturing process, in order to improve the wire life and wire saw machining process.     

Thermal stability of devices with molybdenum oxide doped organic semiconductors

We demonstrate the thermal stability of transition-metal-oxide (molybdenum oxide; MoO₃)-doped organic semiconductors. Impedance spectroscopy analysis indicated that thermal deformation of the intrinsic 1,4-bis[N-(1-naphthyl)-N′-phenylamino]-4,4′-diamine (NPB) layer is facilitated when the MoO₃-doped NPB layer is deposited on the intrinsic NPB layer. The resistance of the intrinsic NPB layer is reduced from 300 kΩ to 3 kΩ after thermal annealing at 100 °C for 30 min. Temperature-dependent conductance/angular frequency–frequency (G/w-f-T) analysis revealed that the doping efficiency of MoO₃, which is represented by the activation energy (E_a), is reduced after the annealing process.