16MnR钢在含H2S介质中的慢应变速率腐蚀试验研究

通过慢应变速率法(SSRT)应力腐蚀试验,研究了16MnR钢的H2S应力腐蚀敏感性,修正了计算应力腐蚀敏感性指数的方程.结果表明,水溶液中pH值对16MnR钢的应力腐蚀影响较大,16MnR钢的应力腐蚀敏感性H2S浓度应该根据pH值确定.     

碳酸盐硫化氢复杂环境中16MnR钢应力腐蚀敏感性研究

采用慢应变速率拉伸试验研究了16MnR钢在碳酸盐和硫化氢复杂环境中的应力腐蚀开裂敏感性.结果表明,在含碳酸盐和硫化氢的复杂介质环境中,16MnR钢的应力腐蚀敏感性指数低于25%;温度由常温升高至57.5℃时,16MnR钢母材与热影响区的应力腐蚀敏感性略有升高,碳酸盐和硫化氢浓度对16MnR钢在此复杂环境中的应力腐蚀敏感...     

16MnR系列材料在油田H_2S-CO_2-Cl~-环境下的耐蚀性

通过应力腐蚀试验及全面腐蚀试验,系统地研究了16MnR系列压力容器用钢在油气田高含H2S-CO2-Cl-环境下的抗腐蚀性能,分析了16MnR系列钢在这种工况条件下作为压力容器用材的适用性。结果表明,16MnR(HIC)母材和焊接接头满足抗硫化物应力开裂(SSC)的基本要求,可以在pH值6以上、50℃以下的介质中任意H2S、CO2和Cl-含量下安全使用,其他16MnR材料对硫化物应力开裂(SSC)和氢诱导开裂(HIC)较敏感。在选材时还应在实际模拟工况条件下进行全浸腐蚀试验,以确定其腐蚀速率。     

碳钢渗铝换热器在常减压装置低温部位的腐蚀研究

用双U形恒应变实验方法,研究了20#碳钢、16MnR、碳钢渗铝基材及焊接材料浸泡在不同硫化物浓度的油品介质中的开裂敏感性。实验结果及现场挂片数据表明：焊接材料更易于发生湿H2S应力腐蚀开裂;渗铝钢有更低的H2S开裂敏感性,适宜在常减压装置低温部位换热器上应用。     

16MnR 钢在催化裂化再生环境中的应力腐蚀裂研究简

通过U形试样应力腐蚀实验、电化学极化曲线等方法,在模拟催化裂化再生器环境条件下,研究了HNO3-H2SO4-H2O体系中16MnR钢及其焊缝的应力腐蚀行为。结果表明:16MnR钢焊接接头在不同实验条件下均比基材更易产生硝酸盐应力腐蚀开裂,其机理主要是阳极溶解;引入硫酸根和降低pH值均能破坏16MnR钢的保护膜,增大其焊接接头的应力腐蚀敏感性;当溶液的pH值降低至2以下时,材料处于活化状态,发生严重的均匀腐蚀。     

1Cr13不锈钢在湿H_2S环境中的应力腐蚀行为

对海洋油气井用1Cr13不锈钢进行了慢应变速率试验,并结合扫描电镜分析研究了其在不同腐蚀环境中的应力腐蚀敏感性。通过回归分析软件,建立了1Cr13不锈钢的应力腐蚀敏感指数与各参数之间关系的数学模型。结果表明:1Cr13不锈钢在H_2S体积分数小于0.17%,pH大于3的环境中有较好的抗应力腐蚀能力;交互四次型回归方程可以较好地反映1Cr13不锈钢应力腐蚀敏感指数Iδ与pH、Cl-质量分数、温度和H_2S体积分数等介质参数的关系,并且H_2S质量分数和温度对应力腐蚀敏感指数产生交互作用。     

不同钢制造LPG球罐在湿H2S环境下失效行为的对比研究

对16MnR钢和SPV50Q钢液化石油气(LPG)球罐在湿H2S环境下的失效行为进行了对比研究.通过观察从16MnR钢球罐上所取下的严重腐蚀球壳板的裂纹特 征和SPV50Q球罐内壁所作金相复膜照片的裂纹形貌,以及分析现场所测试的硬度和残余应力,表明：16MnR钢球罐的失效是由氢诱导开裂(HIC)所引起,损伤部位发生在母材上,而SPV50Q钢球罐则是由硫化物应力腐蚀开裂(SSCC)所造成,裂纹主要出现在焊接接头附近的热影响区(HAZ).     

N80#油管钢在含H2S酸性溶液中的腐蚀行为

用稳态极化法、阳极动电位扫描法和交流阻抗法研究了酸性溶液中pH值和H2S的浓度 对N80#油管钢腐蚀行为的影响.结果表明：随着溶液pH值的减小、H2S浓度的增大N80#油 管钢的腐蚀速率加快;HAc NaAc体系中无H2S时,油管钢在活性溶解过程中生成的吸附性 中间产物是Fe(OH)ad,而加入H2S后,则生成了另一种吸附性中间产物—Fe(SH) ad.     

激光冲击处理对X70管线钢焊接接头H_2S应力腐蚀影响

采用慢应变速率法(SSRT)进行了X70管线钢焊接接头在H2S介质中应力腐蚀试验,研究了H2S对X70管线钢焊接接头应力腐蚀开裂(SSCC)的敏感性,分析了激光冲击处理对X70管线钢焊接接头抗H2S应力腐蚀开裂SSCC行为的影响。结果表明,经激光冲击处理后X70管线钢焊接接头表面产生了晶粒细化和残余压应力,提高了管线钢焊接接头在NACE饱和H_2S溶液中抗应力腐蚀性能;原始状态试样在NACE饱和H_2S溶液中慢拉伸试验平均应力腐蚀敏感性指数>25%,有明显的应力腐蚀倾向;经激光冲击处理后试样在NACE饱和H_2S溶液中平均应力腐蚀敏感性指数为19.05%,应力腐蚀倾向不明显,因此,激光冲击处理有效地提高了X70管线钢焊接接头的抗应力腐蚀性能。     

新型超高强度钢Cr12Ni4Mo2Co14在酸性环境中的应力腐蚀行为

采用慢应变速率拉伸实验研究了一种新型超高强度钢在酸性环境中Cl~-和H对应力腐蚀行为的交互作用,并采用SEM观察了试样断口形貌.结果表明,Cl~-显著提高Cr12Ni4Mo2Co14钢的应力腐蚀敏感性,实验条件下临界Cl~-浓度[Cl~-]c为0.15%左右.当Cl~-浓度高于[Cl~-]c时,Cl~-引发严重的点蚀,应力腐蚀裂纹起源于点蚀坑处.Cr12Ni4Mo2Co14钢在含Cl~-溶液中的断裂机理可以用"滑移-膜破裂"机制进行解释.充氢后的Cr12Ni4Mo2Co14钢发生氢致开裂,断口上出现二次裂纹.临界充氢电流密度i_([H]c)为10 m A/cm~2(溶液p H=5,充氢时间为30 min).当充氢电流密度大于i_([H]c)时,Cr12Ni4Mo2Co14的强度损失和塑性损失趋于最大值.溶液中的Cl~-浓度和材料中的H有复杂的交互作用,并非简单的加和作用.     

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.