一种增强型曼尼希碱酸化缓蚀剂的合成及其性能

以乙二胺、多聚甲醛和苯乙酮为原料经曼尼希反应合成了乙二胺双曼尼希碱盐酸盐,并合成了2-苯甲酰基-3-羟基-1-丙烯(BAA)和3-羟基苯丙酮,使用核磁共振氢谱分别对其结构进行了表征。三者复配得到增强型酸化缓蚀剂,采用静态失重法,电化学方法和SEM观察等研究了复配缓蚀剂在15%HCl溶液中对N80钢的缓蚀性能。结果表明:在90℃、15%HCl溶液中加入0.1%复配缓蚀剂,N80钢片的腐蚀速率为2.316 2g·m~(-2)·h~(-1),即达到一级标准(SY/T 5405-1996)。此外,该缓蚀剂是一种混合型缓蚀剂,在N80钢片表面的吸附作用符合Langmuir等温吸附规律。表面分析试验(SEM和EDS)验证了缓蚀剂分子在N80钢片表面形成了一层保护膜。     

一种双缩水合肼Schiff碱的合成及其酸化缓蚀性能

以水合肼和肉桂醛为原料合成了一种新型Schiff碱酸化缓蚀剂(DCH),用红外光谱法(FI-RT)、化学元素分析法和核磁共振法对其结构进行表征;通过静态失重法和电化学方法考察了其在15%(质量分数,下同)HCl中对N80钢的缓蚀作用。结果表明:DCH是一种混合型酸化缓蚀剂,可在N80钢表面形成保护膜,有效抑制酸液的腐蚀;当DCH加入量为0.75%时,N80钢的腐蚀速率为2.27g·m~(-2)·h~(-1),缓蚀率高达99.81%;DCH在N80钢表面的吸附规律符合Langmuir吸附模型。     

曼尼希碱季铵盐酸化缓蚀剂的合成及性能

合成了一种新型的曼尼希碱季铵盐(BMQA)酸化缓蚀剂,通过静态失重法测试了缓蚀剂在不同浓度盐酸中的缓蚀性能。结果表明,90℃下,缓蚀剂BMQA在15%盐酸中加入0.1%,18%盐酸中加入0.2%,28%盐酸中加入0.5%,N80钢的腐蚀速率都能小于4g·m-2·h-1。极化曲线测试表明该缓蚀剂是抑制阳极为主的混合型缓蚀剂,遵循Langmuir吸附等温式,能自发在金属表面进行化学吸附。     

两种曼尼希碱缓蚀剂的缓蚀性能

采用甲醛/苯甲醛、苯乙酮和水合肼为原料分别合成了AJ和BJ两种曼尼希碱缓蚀剂。通过静态挂片失重法、电化学测试法等方法研究了在15%HCl(质量分数)溶液中,这两种缓蚀剂对N80钢的缓蚀性能。结果表明:在15%的HCl溶液中,AJ和BJ缓蚀剂对N80钢具有良好的缓蚀作用,且BJ缓蚀剂的缓蚀效果要优于AJ缓蚀剂的;两种缓蚀剂均为阳极型缓蚀剂,都能自发吸附在N80钢表面,其行为均符合Langmuir吸附等温式。     

曼尼希碱缓蚀剂的合成及其缓蚀效果

以甲醛、苄叉丙酮、对甲基苯胺为原料,通过曼尼希反应,制备了一种新型的曼尼希碱缓蚀剂(MHX),并采用正交试验优化了制备条件。采用静态失重法、电化学测试及分子动力学模拟的方法,研究了MHX添加量对N80钢片在HCl溶液中缓蚀效果的影响。结果表明：在90℃、添加1%MHX的20%HCl溶液中,N80钢片的腐蚀速率为2.6 g·m^-2·h^-1,缓蚀率为99.63%;该缓蚀剂是一种以抑制阳极为主的混合型缓蚀剂,可以大幅降低腐蚀电流密度,提高电极阻抗;MHX能够在N80钢表面吸附成膜,降低钢表面Fe的损耗,使其表面粗糙度降至93.81 nm; MHX分子在N80钢表面的吸附能为-7.59 eV,能有效取代H₂O分子吸附在金属表面,从而起到缓蚀作用。     

新型希夫碱酸化缓蚀剂的合成及性能评价

以苯胺和芳香醛为原料,通过Schiff反应合成了一种新型希夫碱酸化缓蚀剂ACR-1。采用静态失重法研究了盐酸浓度、腐蚀温度和缓蚀剂浓度对该缓蚀剂缓蚀效果的影响,并对该缓蚀剂在钢片表面的吸附模型进行了探讨;通过电化学法研究了该缓蚀剂的电化学机理。静态挂片失重法表明,腐蚀温度为90℃,腐蚀时间为4h,在ACR-1浓度为1.0%的15%盐酸溶液中,N80钢片的腐蚀速率为1.6733g.m-2.h-1,完全可以满足石油行业标准SY/T 5405-1996一级缓蚀剂产品的指标(3～4g.m-2.h-1);等温吸附行为研究结果表明,该缓蚀剂分子能自发的吸附在N80钢表面上,其在N80钢表面的吸附符合Langmuir单分子吸附模型;电化学法研究表明,ACR-1是一种以抑制阳极反应过程为主的混合型缓蚀剂,属于"几何覆盖效应"模型,并且可以在N80试片表面形成明显的保护性膜层,有效地抑制了试片在酸液中的腐蚀。     

哌嗪类曼尼希碱壳聚糖缓蚀剂的制备及缓蚀性能研究

目的 解决海底采油设备酸化腐蚀问题,合成一种绿色的哌嗪类曼尼希碱壳聚糖衍生物缓蚀剂CS-NMB,并研究其在15%（质量分数）盐酸溶液中对N80钢的缓蚀性能,计算研究其在金属表面的作用机理。方法 以曲酸和N–甲基哌嗪为原料,经过曼尼希反应,合成曼尼希碱（MB）,再将该曼尼希碱接枝到壳聚糖分子上。采用红外光谱表征所合成产物,利用电化学法和静态失重法评价CS-N-MB在该强酸环境中对N80钢的缓蚀能力。基于密度泛函理论,研究壳聚糖（CS）和CS-N-MB的反应活性,明确活性位点,并通过分子动力学计算缓蚀剂的吸附能以及体系中水分子的均方位移。结果 在15%盐酸环境中,CS-N-MB对N80钢具有良好的缓蚀作用,且当缓蚀剂添加量小于200mg/L时,随着浓度的增加,N80钢的腐蚀速率逐渐减小。当缓蚀剂添加量大于200 mg/L时,短时间内,随着浓度的增加,N80钢的腐蚀速率又略微增大,而72 h后N80钢的腐蚀速率略微减小并趋于稳定。电化学研究表明,CS-N-MB能够同时抑制腐蚀的阴极反应和阳极反应,是混合型缓蚀剂。分子模拟结果表明,CS-N-MB的主要活性位点集中在N、O以及环状结构处,且加入...     

曼尼希碱缓蚀剂CJ的合成及其性能

曼尼希碱是一类重要的金属缓蚀剂。以肉桂醛、环己酮、水合肼为原料合成曼尼希碱缓蚀剂CJ,采用正交试验优化得出最佳合成条件,同时采用极化曲线和电化学阻抗谱等电化学方法研究了曼尼希碱缓蚀剂CJ的缓蚀机理。结果表明:当肉桂醛/水合肼摩尔比为3∶1、环己酮/水合肼摩尔比为1∶1、反应温度为45℃、pH为4、反应时间为8h时,CJ具有最好的缓蚀性能。在15%盐酸中,当缓蚀剂加量为1.0%时,N80钢片的腐蚀速率为0.299 1g/(m2·h),远低于SY/T 5405-1996中的一级标准。曼尼希碱缓蚀剂CJ在钢铁表面的吸附符合Langmuir吸附等温方程;曼尼希碱缓蚀剂CJ是以抑制阳极腐蚀过程为主的混合型缓蚀剂。     

Fe3+对双曼尼希碱(DM)缓蚀性能及吸附行为的影响

目的针对曼尼希碱类缓蚀剂使用工况恶劣、影响因素复杂的情况,以单曼尼希碱为中间体,合成双曼尼希碱缓蚀剂(DM)。方法采用失重法、电化学方法研究Fe~(3+)对DM缓蚀性能的影响,计算DM在N80钢片表面的吸附热力学与动力学,并探讨Fe~(3+)对DM吸附行为的影响。结果在60℃、腐蚀介质总体积250 mL、缓蚀剂(DM)质量分数1%、盐酸质量分数20%、浸泡时间4 h的条件下,当Fe~(3+)质量浓度小于900 mg/L时,其腐蚀速率小于4 g/(m~2·h),满足SY/T 5405—1996对盐酸酸化缓蚀剂一级品的评价指标;当Fe~(3+)质量浓度大于900 mg/L时,其腐蚀速率仍然小于5 g/(m~2·h),满足盐酸酸化缓蚀剂二级品的评价指标。在1%DM的缓蚀溶液中,ΔG_(ads)=-44.86 k J/mol,当溶液中存在Fe~(3+)时,ΔG_(ads)=-42.56 k J/mol,与未加Fe~(3+)的相比,ΔG_(ads)更趋向于-40 kJ/mol。N80钢在20%盐酸溶液中的Ea值为7.10 kJ/mol,加入1%DM和1%DM+600 mg/L Fe~(3+)时的Ea值分别为25.45、23.90 kJ/mol。加入1%DM时,ΔE_(corr)=50 mV;加入1%DM+600mg/L Fe~(3+)时,ΔE_(corr)=30 mV。结论 N80钢在60℃、20%HCl条件下,DM缓蚀效率高达99.8%,是一种混合型缓蚀剂。在N80钢表面的吸附为混合型吸附,且吸附过程是一个自发、放热的过程,吸附规律服从Langrauir吸附等温式。加入Fe~(3+)后,对DM缓蚀性能起抑制作用,Fe~(3+)并没有改变DM的缓蚀剂类型,且Fe~(3+)通过破坏DM在N80钢表面的化学吸附来降低其缓蚀效率。     

曼尼希碱缓蚀剂在盐酸中对N80钢缓蚀性能

目的制备一种新型曼尼希碱缓蚀剂并研究其性能。方法利用失重法研究缓蚀剂缓蚀效率与缓蚀剂的质量浓度、盐酸质量分数、腐蚀温度、腐蚀时间的关系,确定缓蚀剂的吸附曲线。通过动电位极化曲线法和交流阻抗法研究缓蚀剂的综合性质。利用扫描电镜观察腐蚀前后N80钢片的表面形态。结果缓蚀剂缓蚀效率随缓蚀剂添加量的增大而增大,随测试温度的升高而下降,随盐酸质量分数的升高先增大后减小,随腐蚀时间的延长先增大后减小。60℃时,在质量分数为15%盐酸中浸入4 h、缓蚀剂添加量在1.0 g/L的条件下,缓蚀剂缓蚀效率为99.18%,腐蚀反应的活化能由56.34 k J/mol提高到了86.54 k J/mol。缓蚀剂在N80钢表面符合Langmiur吸附模型,吸附吉布斯自由能为-29.94 k J/mol。极化实验结果显示该缓蚀剂为以阴极抑制为主的混合型缓蚀剂。阻抗谱图显示添加缓蚀剂后,阻抗明显增大。扫描电镜结果显示缓蚀剂有效抑制了盐酸对N80钢片的腐蚀。结论所制备的缓蚀剂在质量分数为15%的盐酸中对N80钢片有良好的缓蚀效果。     

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.