新型高压水压试管机端头自密封装置的研制

为保证钢管质量,相关标准要求对钢管进行水压试验。传统的水压试管机存在生产效率低,使用和维护成本高,管端存在试压盲区等不足。介绍了一种新型高压水压试管机端头密封装置,可用于双线管材水压试验设备。其突出特点是,当钢管内充满高压水后,由于水压的作用使密封圈发生变形从而起到自密封作用。该密封装置适合于钢管超高水压外径密封。     

大直径直缝焊管用40MN水压试验机组及其流体系统的设计开发

为满足钢管生产企业对大直径钢管进行承压能力试验的需求,太原重型机械集团有限公司设计开发了大直径直缝焊管用40MN水压试验机。该水压试验机组试验压力高,适应产品规格广,生产节奏快。简述了该机组的设备构成、主要技术参数及试验流程;重点介绍了该机组流体系统的设备组成和参数设计以及设计特点等。     

超高压水压试验机设计技术探讨

本文对超高压水压试验机的工艺特点及液压差动缸补偿装置的作用原理和设计计算进行了分析和探讨。     

基于有限元的叶轮机外壳铸造工艺设计

以叶轮机外壳铸件为研究对象,采用Pro/E和Any Casting软件对叶轮机外壳铸件充型和凝固过程进行了模拟。依据叶轮机外壳铸造过程中产生的缺陷,对其铸造工艺进行了优化设计。工艺优化后铸件质量得到了改善。     

甘肃蓝科石化高新装备股份有限公司研制成功50MN大直径钢管高压水压试验机

<正>2011年5月6日,甘肃蓝科石化高新装备股份有限公司研制的50MN(5000t)大直径钢管高压水压试验机通过出厂验收,将交付用户使用。甘肃蓝科石化高新装备股份有限公司自1997年研制出国内首台全自动水压试验机以来,已向有关企业提供了80台水压试验机。最新研制成功的50MN大直径钢管高压水压试验机在钢管密封、传动、灌注、加压、保压、比例控制等方面集     

钢管水压试验机特性仿真分析

宝钢钢管厂3#油井管线水压试验机是一台集机械、电气、液压、传感、自动控制及计算机等技术为一体的现代化设备,在功能上很好地满足了钢管的水压试验要求,但在使用中也出现了一些问题,尤其是平衡缸位移超差问题.本文作者在建立增压系统与平衡系统数学模型的基础上,对水压试验机的特性进行了仿真分析.     

基于三管水压试验机的试压工艺过程探讨

为提高水压试验的效率,本文研发了一台同时对三根钢管进行压力试验的水压试验机。文章就三根钢管同时进行压力试验提出合理有效的方案,对试压的工艺过程进行分析,针对管径Φ48.3~Φ194 mm定尺钢管在提高生产效率上的实用性进行探讨,满足设计要求。     

我国首条双头高压水压试验机生产线的研制

介绍了西安重型机械研究所研制开发的国内首条双头高压水压试验机生产线的结构特点和性能参数。该水压试验机中增压器与充水头设计成一体,排气头采用了机械丝杆螺母传动形式,试压钢管的密封采用了具有国际先进水平的轴向预压紧大间隙组合密封圈,还采用了具有先进水平的小流量泄露监测报警装置。该生产线已顺利投产。     

Ф140min～Ф426mm钢管水压试验机液压系统的安装调试

水压试验机是对油套管、流体管等钢管进行打压试验的生产线。本文介绍了Ф140mm-Ф426mm钢管水压试验机液压系统的组成及主要特点，论述了该液压系统的安装调试过程，阐明了该系统的功能和作用，并对调试过程中出现的主要故障和排除方法进行了分析，对类似的插装单元具有一定的借鉴意义。     

承压设备水压试验自动控制装置设计与实现

针对当前承压设备水压试验手动加压过程难以控制和采用肉眼直接观察压力表判断水压试验合格性存在误差的问题，提出一种承压设备水压试验自动控制装置设计方案，并实现了装置结构和控制系统。该自动控制装置结构设计包含工作台结构设计、加压管路设计、泄压管路设计和其他保护设计；以PLC、变频器和比例阀为硬件核心，结合模糊PID控制器实现对水压试验过程控制；利用开发的上位机软件实现水压试验设备的人机交互；进行水压试验自动控制装置性能测试。结果表明：该装置能较好地实现水压试验全过程控制和合格性判定，具有对试验过程录像、试验数据实时保存等功能，且可追溯水压试验过程。     

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.