连续立式钢带镀铜生产工艺的研究

1.前言氰化物连续钢带镀铜生产线在国内首次投入工业试生产。它在设备上不同于一般的浸挂镀铜,是采用立式连续镀铜,镀槽分储液槽和工艺槽。工艺槽用高弹橡胶密封,利用泵把镀液从储液槽打入工艺槽进行工作。工艺上要求快速、高效率地镀铜,而通常氰化物镀铜的阴极电流效率较低,一般为60～     

武钢连续电镀锌机组电镀段技术特点

介绍了武钢连续电镀锌机组工艺段设备布置,以及电镀段主要设备特点。该机组电镀段采用先进的重力槽,高效节能的两级闪蒸装置和完善的电镀循环系统,保证了机组产能及产品质量。     

水溶液镀铂

介绍和比较17种水溶液镀铂槽液和电镀工艺,认为酸性P盐槽和硫酸二亚硝基亚铂酸槽的性能优于其它镀铂槽。     

宝钢1550冷轧电镀锌机组镀液蒸发装置改造

宝钢三期1550电镀锌机组自投产以来，电镀工艺槽及其循环系统存在两个大的问题：蒸发装置不能正常投入使用，及电镀槽中带钢湿润系统有缺陷，带钢在镀槽区域产生严重的“电镀斑”，影响产品质量。根据对电镀系统特别是对蒸发装置的分析结论，通过改变蒸发装置的处理对象及加大湿润系统的能力并增设了精细过滤器。一次改造解决了上述两个问题，使蒸发装置的能力及使用范围得到了极大的解放。并由此解决了湿润水的水量增多所带来的镀液增多，离子浓度波动大等问题，从而取得了明显的经济效益。     

铝及铝合金的无色化学氧化

研究一种铝及铝合金化学氧化新工艺,工艺特点是利用低浓度氧化液,在铝工件表面形成无色氧化膜,能显著提高工件耐蚀性,保持基体的光泽,工艺简单,槽液稳定。     

化学镀镍磷合金镀层的原理与应用

目前化学镀镍磷已形成了完善的工艺,获得镍磷合金的化学镀镍槽液,一般又可分为酸性和碱性两大类,由碱性槽液中获得的镍磷镀层其含磷量均小于7％,一般介于2～5％之间,均在较低温度下操作(35～60℃),用于塑料和其他非金属基体上沉积镍层。酸性槽液中获得的镍磷     

铝及铝合金硬质阳极氧化新工艺的研究

论述研制铝及铝合金在40℃下的硬质阳极氧化的新工艺。槽液的主要成分是硫酸、草酸、酒石酸和三乙醇胺,铝及铝合金经阳极氧化处理后,氧化膜硬度高、外观光亮、抗腐蚀性强。该工艺在提高铝硬质阳极氧化槽液温度、增加膜的硬度和节能等方面都县有很大的实用价值。     

化学沉积黑镍薄膜工艺及性能的研究

通过初步筛选和正交优化设计,研制开发出一种新的化学沉积黑镍薄膜工艺,并对槽液 各组分对膜层黑度的影响进行了讨论,得出硫代硫酸钠,硫酸锌是黑色成膜的决定因素,复合添加剂具有稳定槽液,提高膜层黑度的作用。     

铝合金阳极氧化膜中温无氟封孔剂

筛选封孔液主盐及辅助成分,以正交试验法优化铝阳极氧化膜中温无氟封孔剂的配方及工艺。该封孔剂工艺配方独特,封孔质量好,槽液易于管理,经济效益显著。     

铝及铝合金氧化电解着色研究

本文论述了铝及铝合金经三酸阳极氧化后,在镍-锡混合盐槽液中进行交流电解着色时的各工艺参数(交流电压,加压方式,槽液温度及时间)对着色膜的影响。总结出最佳着色电压,并在此基础上获得颜色色泽基本一致的T-t曲线变化规律和控制范围。膜层性能良好,整个工艺有一定的实用价值。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

冲压圆点连接机理初探

对冲压圆点连接的机理和圆点处的金相组织进行了分析。冲压圆点连接可分为4个阶段 ,即板料初压入阶段、冲压圆点成形初期阶段、冲压圆点形成阶段、保压阶段。由于被连接的板料在冲压连接圆点处受挤压 ,所以在材料的连接处产生压应力 ,提高了连接的抗疲劳强度。此外 ,对冲压圆点连接的特点、应用范围及影响因素进行了论述     

Simulation of 3-D Deformation and Material Flow During Roll Forging Process Using System of Oval-Round Groove

Basing on the analysis of the traits of the roll forging process, a system-model of computer simulation has been established. Three-dimensional rigid-plastic FEM has been used for the simulation of the deformation process in the oval and round pass rolling, including the entering, rolling, and separating stages. The analysis was conducted using the Deform-3D ver.5.0 code. The important information concerned with the deformation area characteristic, material flow, and velocity field has been presented. Otherwise,the location of the neutral plane in the deformation area was shown clearly.     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Numerical Simulation of the Thermo-Mechanical Process for Beam Blank Continuous Casting

The aim of this study was to simulate the solidification process of beam blank continuous casting, and then find the reasons for the typical defects of the beam blank. A two-dimensional transient coupled finite element model has been developed to compute the temperature and stress profile in beam blank continuous casting. The enthalpy method was used in the heat conduction equation. The thermo-mechanical property in the mushy zone was taken into consideration in this calculation. It is shown that at the mold exit the thickness of the shell had its maximum value at the flange tip and its minimum value at the fillet. The temperature had a great fluctuation on the surface of the beam blank in the secondary cooling zone. At the unbending point, the surface temperature of the web was in the brittleness temperature range under the present condition. To ensure the quality, it is necessary to weaken the intensity of secondary cooling. At the mold exit the equivalent stress and strain have higher values at the flange tip and at the web. From the spray 1 to the unbending point, the maximum values of stress and strain gradually moved to the internal section of the flange tip and the web. However, whenever, there were bigger stress and strain values near the flange tip and the web than in the other parts, it must be very easy to generate cracks at those positions. Now, online verification of this simulation has been developed, which has proved to be very useful and efficient to instruct the practical production of beam blank continuous casting.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.     

The Electrochemical Behavior of Oceanic Microbiological Influenced Corrosion on Carbon Steel

The corrosion behavior of carbon steel in the medium of marine microorganisms was investigated by electrochemical impedance spectra, polarization curves, and so on. Experimental results showed that the corrosion potential of carbon steel moved in a negative direction in the unpurified marine microorganism solution, and the polarization style of the cathodic process did not change. The electrochemical impedance spectra showed that the impedance value of the electrode decreased in the medium with bacteria, which indicated that the existence of microorganism could accelerate the corrosion progress of carbon steel.     

Structural Optimization of Electromagnetic Swirling Flow in Nozzle of Slab Continuous Casting

During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality of the slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, thereby controlling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle and partly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structure and angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower than that without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at the top surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial to the growth of equiaxed crystal and decreased element segregation.     

Effect of Structural Parameters on the Thermal Stress of a NiFe2O4-Based Cermet Inert Anode in Aluminum Electrolysis

Inert anode has been a hot issue in the aluminum industry for many decades. With the help of FEA(finite element analysis) software ANSYS,a model was developed to simulate the thermal stress distribution working condition of an inert anode. To reduce its thermal stress,the effect of some parameters on the thermal stress distribution was investigated,including the anode height,the anode radius,the hole depth,the hole radius,and the radius of inner chamfer and outer chamfer. The results showed that in the actual working condition of an inert anode,there existed a large axial tensile stress near the tangent interface between the anode and bath,which was the major cause of anode breaking. Increasing the anode height and reducing the hole depth properly seemed to be beneficial for the stress distribution. With the increase of anode radius,the stress distribution became better first and then deteriorated,the reasonable value was between 0.045 to 0.06m. The hole radius had a significant effect on the stress and a smaller radius would reduce the thermal stress. The effect of the radius of the inner chamfer and the outer chamfer was less than other parameters.     

RESEARCH ON THE FORMATION MECHANISM OF INTERNAL CRACK IN THE CONTINUOUS CASTING SLAB

In view of the periodic bending deformation of solid-liquid interface in the solidification process for continuous casting slab, the variation of temperature gradient and dendritic spacing in the front edge of the solid-liquid interface, and the nucleation and propagation process of crack were studied. It is shown that the bending deformation of the interface results in the temperature field change in the front edge of solid-liquid interface, and the occurrence of temperature gradient along drawing direction results in the growth of secondary dendrites. The initial crack formed during the middle and final stage of solidification may extend to the surface of the casting slab and become an internal crack. The results of the theoretical analysis are basically in agreement with that of the experiment.