液压摆式直角剪板机设计

针对较长复合钢板经爆炸焊接后需剪切两不规则边的需求,设计了两台对称的液压摆式直角剪板机。该机在常用液压摆式剪板机基础上,增加了侧刀装置,压料油缸采用活塞油缸。两台机床同时对不规则边多次剪切,采用较小规格的剪板机完成了较长板料的修边剪切。     

液压摆式剪板机刀片调整方法

剪切前角和间隙对保证剪板机剪切质量起着非常重要的作用。液压摆式剪板机由于依赖刀架旋转实现剪切过程,其剪切过程必然存在剪切前角和间隙的变化。本文通过分析液压摆式剪板机刀片的安装要求和剪板机刀片的一般调整方法存在的问题,提出了一种有利于减少剪板机剪切间隙和保证工作前角稳定的刀片调整方法。     

新型全液压传动摆式剪板机试制成功

上海冲剪机床厂在参考法国SAGITA液压摆式剪板机CP系列的基础上,自行设计并试制成功QC12Y—4×2500型液压摆式剪板机。在今年6月底召开的新产品鉴定会上受到了用户和外贸部门的好评。该机的主要结构特点是:     

摆式剪板机刀架设计中应考虑的因素

摆式剪板机剪切力计算一般按直线运动刀架剪板机剪切力计算式进行计算.而简化刀片安装面加工工艺后,摆式剪板机剪切间隙和剪切前、后角会随着剪切的进行发生变化,严重影响剪切质量,甚至损坏剪板机机架或使刀具出现早期损坏.为此,在剪切力计算和刀架设计中必须考虑这一情况,分别作适当补偿或改进.本文从理论上推导出了摆式剪板机剪切间隙和剪切前、后角的计算公式,并结合情况初步给出了补偿意见和改进方法.使摆式剪板机的设计更趋近于其实际工作情况,进而提高摆式剪板机的剪切质量,降低故障发生率.     

摆式剪板机刀架的有限元分析

摆式剪板机主要组成部分刀架和机架,它们强度和刚度直接决定了剪板机的刚性和剪切精度。本文以QC12Y-6×3200为例,对摆式剪板机的刀架进行建模分析,判断出关键位置和静力学性能,为改进产品结构、提高设计质量提供重要依据。     

一种新型摆式剪板机的液压传动系统

老式液压摆式剪板机液压系统结构复杂，由于靠系统本身来保证双缸同步，因而精度低，造价高、系统集成困难。此外，由于工作油液压力高，极易造成渗漏油，故给机器维护带来了极大的困难。针对上述问题，我们开发了一种新型数控摆式剪板机。其液压系统（下图）设计独特，具有传动效率剪板机液压原理图高、结构简单、可靠性高及易集成等特点。系统采用双缸并联，利用液压缸直径的不同，来克服刀架在剪切板材时产生的扭转，抵消刀架的扭转变形。通过增加刀架的刚性来实现双缸刚性同步，保证同步精度。系统主要由柱塞泵２、插装阀４、电磁换向阀…     

荷兰达利公司产品简介

1.摆式剪板机(S 系列)剪切宽度为1250～3100mm、厚度为0.5～4.0mm 的板料。按摆式原理配有简单的液压驱动机构。S 系列剪板机是按 GS 系列大型剪板机设计的,具有简单可靠、操作方便、牢固的钢板焊接结构、防止超负荷等优点。此外,摆式剪切机还具有下述特点:剪切速度高(1.5m/s),剪切精度高,寿命长,无导轨。剪切间隙调节简便迅速,剪刀调节方便,上下剪刀都具有四个剪切刃,工作台上有 T 形槽,可堆放和支托板料,并配有送料滚珠。圈1为 S 系列剪板机。     

QZ12K－6×3200型数控液压摆式剪板机

ＱＺ１２Ｋ－６×３２００型数控液压摆式剪板机ＱＺ１２Ｋ－６×３２００型数控液压摆式剪板机于１９９６年３月在浙江试制成功。该机可剪板厚６ｍｍ，可剪板宽３２００ｍｍ，数控轴数为１轴，后挡料最大距离６００ｍｍ，后挡料调节最大速度６ｍ／ｍｉｎ，后挡料调节定位...     

Q12Y—32×4000型液压摆式剪板机

我厂在一九七六年高举“鞍钢宪法”伟大红旗,坚持独立自主、自力更生方针,大干快上,经过五个月的时间,就自行设计试制了Q12Y—32×4000型液压摆式剪板机(见封四)。这台剪板机的试制成功为我国剪板机系列填补了空白。这是毛主席革命路线的伟大胜利,是     

Q12Y—20×2500型液压剪板机

最近,我厂自行设计制造了一台Q12Y～20×2500型液压剪板机。这台剪板机在设计中吸取了黄石、上海、北京制造的同类产品的优点,采用了新的液压传动系统和先进的摆式结构,机架刚性好,零件数量少,使用可靠,维修简单。该机与同类产品相比,有如下特点:     

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.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

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.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.