The Theoretical Study of O_2 Adsorption on NiTi (100) and (110) Surfaces

1　IntroductionNiTishapememoryalloyhaswidelybeenusedinmanyfieldsduetoitsexcellentmechanicalproperties ,uniqueshapememoryeffectandsuperelasticity .In 1970’s ,thegoodbiocompatibilityofNiTialloywasdiscoveredanditwasfurtherusedforvariousbiomedicalapplica tions ,suchasorthopaedicsurgery ,cardiovascularandgas trointestinalsurgery[1-4] .Thehighmechanicalpropertiesandbiocompatibilityofthebiomedicalmaterialsarenec essaryfortheirefficientuseinhumanbody .Thecorrosionresistanceofthealloyandthetoxicityo…     

低(超低)碳贝氏体钢DB590R的研制

研制了600MPa级低（超低）碳贝氏体钢DDB590R。试验分别在实验室和热连轧生产线上进行,通过控轧控冷两阶段轧制。分析了试验钢的组织结构、力学性能和系列冲击韧性。实验结果表明,试验钢的化学成分设计合理,具有优良的综合力学性能：该钢在强度方面具有较大的富余量,屈服强度的平均值为561MPa,抗拉强度的平均值高达645MP;其韧性指标也大大地超过了设计目标,－40℃的纵向冲击韧性值为150J以上,韧脆转变温度在－80℃以下,具有极优的冷弯性能。     

钢中夹杂物在车轮成形过程中的变形行为

为研究夹杂物在车轮预成形过程中的演变行为,采用跨尺度有限元法建立车轮预成形二维轴对称宏观模型和含夹杂物体积元细观模型,对夹杂物变形进行仿真,考察夹杂物的变形抗力对夹杂物变形的影响.结果表明:夹杂物变形程度与其相对变形抗力λ呈负相关关系;车轮踏面下23.3 mm位置B,难变形夹杂物(λ=2)和易变形夹杂物(λ=1/2)均出现了应变集中,前者等效应变最大值为3.85、后者等效应变最大值为1.67;车轮踏面下23.3 mm位置B周向和轴向夹杂物有最大尺寸,车轮踏面下35.4 mm位置A及轮缘位置C和D周向和径向夹杂物有最大尺寸,从垂直于最大尺寸方向的方向进行探伤有利于鉴别夹杂物尺寸.     

Corrosion Behavior of Low Alloy Pipeline Steel in Saline Solution Saturated with Supercritical Carbon Dioxide

The carbon dioxide corrosion behavior of low alloy pipeline steel was investigated by immersion experiment. Optical microscopy(OM), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and X-ray diffraction(XRD) were used to reflect the microstructure of the tested material and the corrosion morphology characterization. Results show that precipitate particles may accelerate the iron cabonate crystal formation process of the nucleation growth and promote the formation of compact layer. The major corrosion phases are Fe CO_3 and complexity compound containing Fe and Cr. The corrosion behavior consists of three stages. At the first stage, a thin inner layer and an inhomogeneous outer layer have appeared. At the second stage, the outer layer becomes homogeneous and compact, which prevents corroding the steel substrate further. At the third stage, iron carbonate crystal tends to nucleate and grow locally. The corrosion rate obtained by weight loss method increases abruptly first and then decreases quickly with increasing corrosion time. The mutual relation among microstructure, corrosion surface morphology, corrosion phases and corrosion kinetics is discussed.     

TiN薄膜对碳钢和铬钢耐磨性影响的研究

利用空心阴极离子镀膜机在碳钢(T7A)和铬钢(Cr12MoV)上制备TiN薄膜，采用销一盘式磨损试验机，在润滑条件下，研究了不同基体材料上TiN薄膜的耐磨性．结果表明：铬钢Cr12MoV上的TiN薄膜耐磨性明显好于碳钢T7A上TiN薄膜的耐磨性。     

低浓度硫化氢在浸渍活性炭上的吸附及表征

采用浸渍法改性活性炭吸附净化低浓度H2S,研究了Na2CO3、KOH、KI改性活性炭吸附净化H2S的性能.研究表明:7%(质量分数)的Na2CO3是最佳浸渍液,80℃和氧含量1.0%(体积分数)是改性活性炭的最佳反应条件.改性后的活性炭用氮气吸附的方法测定其孔结构特征,表明改性减少了空隙率,特别是减少了微孔体积.但Na2CO3改性可以显著增加活性炭对H2S的吸附能力,分析表明,存在于微孔中的Na2CO3起了催化作用,使H2S迅速氧化成硫的氧化物(S),而硫的氧化物能较强地吸附在活性炭0.3-0.9nm的微孔中.     

H_2分子在Ni（100）、（110）、（111）单晶表面吸附研究

本文来用改进模型势方法，计算了Ｈ２分子在Ｎｉ（１０Ｏ）、（１１０）、（１１１）单晶表面解离吸附的反应途径与位能面．通过对比研究，讨论了氢分子在镍三种单晶表面解离吸附的反应途径和位能面的一般规律与趋势．     

低碳钢和不锈钢粉末渗铝研究进展

文章介绍了低碳钢、不锈钢粉末渗铝的特点和原理。钢经过渗铝后,表面硬度增加,渗铝层的耐磨性、抗高温氧化性能、耐蚀性均得到提高,在石油、化工、电力等行业具有广泛的应用前景。     

不同镀层热成形钢的腐蚀行为研究

使用循环腐蚀测试、电化学极化曲线、扫描电镜等方法研究了镀铝硅、合金化镀锌热成形钢的腐蚀行为,结果表明:铝硅镀层在热成形后对钢铁基体不具有牺牲阳极保护作用,在腐蚀反应初期,腐蚀溶液可穿透镀层间的裂纹造成基体的腐蚀.长期的腐蚀暴露实验结果表明铝硅镀层热成形钢的腐蚀速率低于镀锌热成形钢.     

低碳钢表面激光涂覆WC+Co的工艺研究

本文研究了利用激光作为热源在低碳钢表面涂覆WC+Co的工艺。利用光镜、扫描电镜、能谱成分分析及显微硬度等手段对涂层合金的组织和性能进行了分析。认为在低碳钢表面涂覆硬质合金的涂层组织性能取决于激光涂覆工艺与预涂层的质量。在较低的激光输出功率和较慢的扫描速率下,可以得到WC颗粒弥散分布于γ为基的固溶体上的组织,其硬度可达1400HV.较高的功率条件下,涂层组织是WC全部熔解重新生成的η+γ共晶组织,硬度降至1000HV.较快的扫描下涂覆层合金不易涂覆在基体上。     

Microstructure and Properties of a Low Carbon Ti-V Microalloyed Steel

Due to the largely inhomogeneous deformation among constituent phases, the advanced high-strength multi-phase steels are always facing challenges when applied to automotive parts where local formability is critically required. In this work, two characteristic microstructures were produced from a low carbon Ti-V microalloyed steel by varying the cooling path. In the ferrite single-phase microstructure resulted from "ultra-fast cooling(UFC) + furnace-cooling(FC)", the hole-expanding ratio of 200% and tensile strength of 647 MPa were achieved. In the ferrite-bainite-martensite(F+B+M) multi-phase microstructure produced by "UFC + air-cooling(AC) + UFC", the ferrite has been strengthened by Ti-V carbides to promote the strain partitioning, which resulted in the tensile strength of ≥780 MPa, a moderate elongation and hole-expanding ratio of 93%. The strengthening contributions of Ti-V carbides were calculated to be 126 MPa and 149 MPa in the ferrite single-phase and F+B+M multi-phase microstructure, respectively.     

低碳钢的解理断裂机理及微观形貌分析

通过对低碳钢的低温冲击试验,研究了解理断裂过程中裂纹的形核、裂纹尖端的受力以及解理裂纹的形成,并结合滑移与解理之间存在＂竞争＂的理论阐述了解理断裂发生的条件.同时,通过扫描电镜对低碳钢断口的观察,清晰地观察到＂连续型＂河流和＂冲击型＂河流两种解理断裂微观形貌,对其形成机制进行了研究.     

低碳马氏体型非调质钢的研究

通过少量碳与适量合金元素Mn、Si和Cr配合,试图制备低碳马氏体非调质钢,研究结果表明:锻造后经1000℃正火处理能够在钢中获得低碳板条马氏体组织以及位于马氏体板条之间的少量稳定残余奥氏体薄膜.具有这一理想组织的钢不需进行回火处理也能使材料具有很高的强度(s=1620MPa,b=1704MPa)和良好的塑性(5=12.1%).     

铜印迹壳聚糖/活性炭复合膜的制备及其吸附性能

微波辐射下,以戊二醛为交联剂、Cu2+为印迹模板,制备壳聚糖/活性炭复合印迹(CCTS)膜。通过扫描电镜对复合印迹膜的结构进行表征,显示膜表面粗糙。CCTS对Cu2+静态吸附条件为:p H=5.5、初始浓度为300mg/L,吸附剂投加量为0.05g,震荡吸附240min,最大吸附量为150.8mg/g。二元离子体系的选择性吸附结果表明,CCTS对Cu2+的吸附具有选择性。     

Effects of Adsorption of Albumin and Gamma-Globulin on the Tribological Performance of a Diamond-Like Carbon Film

The effects of surface adsorption of bovine serum albumin(BSA) and human gamma-globulin(HGG) on the tribological performance of a DLC film were investigated using a quartz crystal microbalance with dissipation(QCM-D), a ball-on-disk reciprocating tribometer, and a three-electrode electrochemical cell. The results showed that the wear depth in the BSA solution was higher than that in the HGG solution. In the HGG solution, the HGG-adsorbed layer could act as a lubricating layer and protect the DLC film from wear. The wear volume of DLC film in BSA and HGG mixture solution was higher than that in single HGG solution. This may be because the BSA molecules inhibit the formation of HGG adsorbed layer during sliding.     

调质处理对低碳贝氏体钢组织和性能的影响

通过对低碳贝氏体钢的调质处理工艺试验,研究不同的淬火介质、淬火温度及回火温度对实验钢组织和性能的影响。结果表明:经过930℃加热保温并10min油淬后,再选取500℃回火70min,实验钢的微观组织为细小的块状铁素体基体上分布着均匀的碳化物。实验钢的硬度由未调质处理前的260.7HV提高到322.2HV。     

低碳钢用硅作发热剂的实验研究

本文研究了采用以Ｓｉ为发热剂低Ｃ钢化学升热法的升温速度和升温范围，测定升温速度为１１．４℃／ｍｉｎ，升温范围为４１．３℃。研究了过剩指数，底吹Ａｒ气流量、氧流量、枪位对升温速度的影响，分析了影响发热剂热效率的主要因素。     

碳钢和纯铜在试验土壤中的腐蚀研究

采用交流阻抗谱和极化曲线测试技术,研究了碳钢和纯铜在4种不同土壤介质中的腐蚀规律．实验结果表明,土壤配制液对碳钢和铜电极的侵蚀性与土壤溶液的pH值有较大关系．     

低碳钢激光膏剂渗碳组织及性能研究

采用在０８＃钢试样表面上涂覆渗碳膏剂，用ＣＯ２激光束进行辐照，结果表明该工艺渗层硬度高、渗碳速度快，说明激光膏剂渗碳是一种很有应用前景的新工艺。