出口油轮大舵杆试锻成功

<正> 1.引言 我厂承接94外014合同中的舵杆为出口油轮中的重要锻件,需经DNV船检并出具DNV证书。该锻件选用83ZC20MNH钢,要求每个锻件T、B两端均做力学性能试验(每端各一拉六冲)。性能要求为σ_h≥430MPa,σ_s≥230MPa,σ_5≥24％,b≥50％。20℃冲击功:K_U_5≥25J。0℃冲击功Kv_x≥32J。粗加工后UT检测按JFSSI3—1982验收。该锻件的主要尺寸特点是杆部直径和头部的方法兰尺寸相差悬殊;且方法兰的对边尺寸很大,是我厂历年来所锻各类舵杆中,方法兰尺寸最大的一种。钢锭选用28t 16角矮胖型真空注锭。我厂最大水压机的     

飞机结构用TC11钛合金异型锻件的组织与性能

介绍了在工业化条件下,通过合理的工艺路线锻制TC11合金异型锻件.并进行了不同热处理制度下异型锻件的组织和性能试验研究.结果表明：采用950℃,2 h空冷＋530℃,8 h空冷热处理后的锻件的显微组织为均匀的α＋β组织,且有较好的综合室温力学性能,其室温性能为：σb：1050MPa～1100MPa,σ0.2：950MPa～1020MPa,δ5：15%～18%,ψ：32%～36%,αku：45.7 J/cm^2～51.7 J/cm^2,其它各项技术性能也符合协议标准要求,满足航空部门需求.     

1.1273碳素结构钢

1. 1273是优质碳素结构钢,有良好的塑性和适当的强度,工艺性能较好,焊接性能尚可,大多在正火状态和调质状态下使用。广泛用于制造各种锻件和热压件、冷拉和顶锻钢材,无缝钢管、机械制造中的零件,如曲轴、转轴、轴销、杠杆、连杆、横梁、套筒、轮圈、垫圈以及螺钉、螺母、摩托车架等。力学性能：抗拉强度为σb≥530（54） MPa;屈服强度为σs≥315（32） MPa;伸长率为δ5≥20%.     

挤压铸造大型铝合金结构件

以大型铝合金结构件为研究对象,探讨了挤压铸造大型铝合金结构件的模具设计原则和工艺参数对产品质量和性能的影响.研究结果表明:在模具温度为200～300℃、浇注温度为740～760℃、加压压力为70 MPa、保压时间为40 s的试验条件下,铸件组织致密、晶粒细化,力学性能达到了同种合金锻件的性能水平(σb≥350 MPa、δ5≥5%)     

SNCM439钢

正SNCM439合金结构钢,执行标准:JIS G4053—2003。对应国产牌号:40CrN iM o A,美国牌号:4340,英国牌号:817M40,816M40。力学性能:抗拉强度σb≥980 MPa;屈服强度σs≥835 MPa;伸长率δ5≥12%;断面收缩率ψ≥55%;冲击功Akv≥78 J;冲击韧性值αkv≥98 J/cm2;硬度268 HB。试样毛坯尺寸为25 mm。     

Q890E高强度调质钢锻件成分及热处理工艺研究

应用于TZM1200全路面伸缩臂起重机的Q890E材质的锻件种类多、批量大、技术要求高,调质后力学性能需满足凡≥890MPa．凡．在940～1100MPa之间,A≥11％,KV2≥27J（-40℃）。GB／T16270-2009要求的Q890E材料的化学成分范围宽泛．所以确定较准确的化学成分、调质热处理工艺及力学性能检测（尤其是低温冲击）成为研究重点。     

0Cr17Ni7Al不锈钢

正0Cr17Ni7Al是沉淀硬化型不锈钢,美国牌号631。因添加铝在海水和其他各种介质中,耐腐蚀性比0Cr19Ni9好。主要用作耐点蚀材料如弹簧、热圈及计器部件。力学性能:抗拉强度σ_b固溶态≤1030 MPa、565℃时效≥1140 MPa、510℃时效≥1230 MPa;条件屈服强度σ_(0. 2)固溶态≤380 MPa、565℃时效≥960 MPa、510℃时效≥1030 MPa;伸长率δ_5固溶态≥20%、565℃时效≥5%、510℃时效≥4%;断面收缩率ψ565℃时效≥25%、510℃时效≥10%;硬度固溶态≤229 HB、565℃时效≥363 HB、510℃时效≥388 HB。执行标准:GB/T 1220—1992。     

灰铸铁缸体本体取样位置及力学性能标准的探讨

为了真实反映和掌握缸体铸件具有的力学性能,分析了缸体本体取样位置和本体力学性能标准。分析表明:铸铁缸体本体力学性能取样位置有3种:缸筒、轴座和其它位置。对干式缸套又不镶缸套的缸体,缸筒位置取样最好;对湿式缸套缸体,可在轴座上取样;其它位置的取样方式一般不采用。HT250和HT300缸体力学性能标准分别是:缸筒σ_b≥225MPa和缸筒σ_b≥260 MPa。HT250轴座σb≥200MPa。硬度也是如此,两种材料的硬度分别为180~230HB和190~230 HB。更重要的是缸筒ΔHB,ΔHB10 HB最好,ΔHB25 HB可判为不合格。     

G51150合金结构钢

<正>美国芬可乐合金结构钢。具有淬透性好的渗碳钢,表面硬度高,耐磨性好。可用于制造齿轮、蜗轮、塑料模具、汽轮机油封和汽油套等。力学性能:抗拉强度σb≥735(75)MPa;屈服强度σs≥490(50)MPa;伸长率δ5≥11%;断面收缩率ψ≥45%;冲击功Akv≥55 J;冲击韧性值αkv≥69(7)J/cm~2;硬度≤179 HB。试样毛坯尺寸为15 mm。     

柴油机连杆热处理工艺改进

某船用柴油机厂选用45钢作为船用柴油机连杆(!85 mm)材质,在批量生产中,经正火(850℃空冷+550￣590℃回火)处理后发现大批量为不合格品,后改为调质(850℃油冷+640￣690℃回火)处理,其力学性能仍不能达到设计技术指标设计要求:σb≥600 MPa;σs≥300 MPa;δ5≥16%;ψ≥40%;Aku5≥20 J;硬度:162～217 HBS。针对上述热处理造成连杆力学性能不合格情况,对连杆进行分类,从材料成分、冷却方式方面进行分析发现,正火处理后,不合格的连杆其含碳量为0.42%～0.46%,属于低含碳量,虽然冲击功达到要求但强度却不能满足;调质处理后不合格的连杆,其含碳…     

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.