50CrVA钢齿形链链板的热处理工艺试验

通过对50CrVA钢齿形链板进行等温淬火后的显微组织和性能分析研究,结果表明,当该链板钢等温温度不变时,提高淬火温度可以提高等温淬火后的贝氏体含量,且硬度基本不变.该钢最佳等温淬火工艺为900℃×20 min奥氏体化,300℃等温35 min,再经200℃回火120min,硬度达到52～53.5 HRC,疲劳寿命大于1×107次.     

热处理对X65抗酸管线钢抗HIC性能的影响

通过金相、扫描电子显微镜的表征手段和抗HIC性能测试,研究了不同调质工艺（940 ℃淬火,530 ℃/580 ℃/630 ℃回火）和940 ℃正火对TMCP态X65 抗酸管线钢的显微组织和抗HIC性能的影响。结果表明,热处理前后三种X65管线钢的抗HIC性能均满足API 5L规范中酸性服役条件PSL2钢管在A溶液中的验收极限。调质处理后的X65抗酸管线钢厚度中心由M/A岛偏聚形成的带状组织消失,各项力学性能均满足API 5L规范对X65钢级管线钢的要求,抗HIC性能较TMCP态显著提高;940 ℃正火处理后的X65抗酸管线钢沿轧制方向形成了珠光体带状组织,其抗HIC性能和拉伸性能较TMCP态降低。     

不同变形条件下管线钢组织及屈服性能的研究

以X70、X80和X100级管线钢为研究对象,通过光学显微镜和力学性能测试,分析不同变形温度对其微观组织及屈服性能的影响。结果表明,经500℃拉伸变形后,X100级管线钢组织中细小的马氏体-奥氏体岛(M-A岛)和下贝氏体组织可提高钢的屈服性能;当变形温度为800℃时,X70、X80和X100级管线钢的高温屈服强度差别不大。     

X80管线钢冲击韧性研究

采用"系列温度冲击试验法"测定了一种X80管线钢在-100～20℃的冲击功,分析了该管线钢冲击断口的分层现象以及冲击韧性的影响因素.综合冲击吸收功、脆性断面率及断口形貌,确定了其韧脆转变温度为～83℃.对于高钢级管线钢,可通过采用先进的冶炼工艺和控轧控冷工艺严格控制化学成分、获得细小的晶粒和均匀的针状铁索体组织,来提高钢的冲击韧性、降低韧脆转变温度.     

X70管线钢高温回火工艺研究

通过金相组织观察和室温横向拉伸、-20℃横向冲击及-15℃落锤撕裂性能测试,研究了不同高温回火温度对X70管线钢组织性能的影响。结果表明,500~650℃回火时,X70管线钢的组织主要为针状铁素体,屈服强度在500 MPa以上,抗拉强度在600 MPa以上,完全能满足X70管线钢对强度的要求。而回火温度超过750℃时,X70管线钢含有大量的多边形铁素体,-20℃横向冲击功降到193J,-15℃落锤剪切面积百分数只有82%,850℃回火时,屈服强度只有340 MPa。综合比较,X70管线钢在500~650℃回火、保温25 min的条件下综合性能较好。     

热煨制过程对X100管线钢组织与性能的影响

对X100管线钢采用淬火-回火型弯制技术制备弯管时的组织与性能进行了研究。结果表明,对于组织中分布有弥散残留奥氏体和Fe3C的粒状贝氏体管线钢X100而言,当回火温度为550℃时,其组织均匀性最好,材料硬度适中。当煨制热制度为950℃淬火＋550℃回火时,其显微组织为贝氏体、多边铁素体和珠光体,硬度可与母材相匹配。冲击断口分析表明,在-20℃时,X100钢断口的纤维区、放射区、剪切区都有良好的韧窝形状,表明在该煨制加热制度下,X100钢可获得良好的韧性。     

热处理工艺对X52热轧管线钢组织和性能的影响

通过分析不同工艺处理后的X52热轧(HR)管线钢母材的组织和性能,得出热处理工艺对热轧态管线钢组织和性能的影响,为相近或相同钢级热轧态管线钢无缝钢管、弯管、管件的热加工及热处理提供实践数据和依据.     

优化控冷制度改善X120管线钢的组织和性能

研究了热轧后四种不同的冷却制度对X120级管线用钢组织、性能的影响。结果表明,该管线钢在相同的控轧制度下,以冷速61℃/s、终冷温度370℃的冷却制度,能得到以贝氏体为主且强度和韧性均达到X120各项性能指标的组织。     

回火工艺对X120管线钢组织与性能的影响

利用扫描电镜(SEM)、透射电镜(TEM)等实验方法,研究了回火温度500～650℃对X120管线钢组织和性能的影响。运用Ashby-Orowan修正模型等强化理论分析了X120管线钢回火工艺的强化机理。结果表明:回火温度对屈服强度和抗拉强度均有较大影响,回火后实验钢屈服强度分别在回火温度为550℃和600℃出现两个峰值,抗拉强度在600℃时出现峰值,伸长率略有升高,屈强比升高。分析认为:回火过程中实验钢性能的变化是由析出强化、位错强化、固溶强化等强化机理共同作用造成的。     

25CrMnMo钢强韧化研究

研究了热处理对新型热轧调质无缝油管用 2 5CrMnMo钢性能的影响。试验结果表明 ,该钢在 92 0℃保温 30min水冷 ,6 5 0℃回火 70min后有较好的强度和韧性。通过选择不同的调质工艺可以满足API 5CT标准中N80Q和P1 1 0等高钢级油管的性能要求     

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.     

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.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

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.