Effect of copper ion implantation on corrosion morphology and corrosion behavior of LaFe_（11.6）Si_（1.4） alloy

The morphology analysis and electrochemical method were used to study the corrosion behavior of LaFe11.6Si1.4 alloy of copper ion implantation. X-ray photoelectron spectroscopy (XPS) and atomic emission spectroscopy (AES) research results showed that a 15 nm-thick oxide film was formed on the surface of sample, and the copper content reached the highest value at 60 nm with a normal distribution. Immersion experiments indicated that the corrosion happened in the copper-poor zone firstly and a galvanic connection was formed among different zones on the surface due to the inhomogeneous distribution of copper. Electrochemical experiment results showed that the corrosion was serious when the ion acceleration voltage increased, and the high acceleration could reduce the thermodynamic performance of corrosion of LaFe11.6Si1.4 alloy.     

Analysis of Surface Longitudinal Crack of Slab and Crack of Cold Bending for Cu-P-RE Weathering Steels

The surface morphology of longitudinal crack at corner of slab and the crack morphology of cold bending for Cu-P-RE weathering sleels were analyzed by metalographic examination and SEM.The feature of erack and the composition of inclusions on the surface of erack were detected by EMPA,     

Characterization and corrosion behavior of Al–Co–rare earth (Ce–La) amorphous alloy

A new Al-based amorphous alloy with excellent corrosion resistance and high thermal stability was produced in the Al–Co–RE (Ce–La) system. In this regard, two different amorphous-nanocrystalline ribbons: Al_87.6–Co_6.4–Ce_3.8–La_2.2 (M₁) and Al_82.3–Co_10.1–Ce_4.8–La_2.8 (M₂) were prepared using melt spinning. The results reveal the supercooled liquid region (ΔT_x) of 218 °C which shows that the M₂ alloy has higher thermal stability in comparison to the M₁ alloy. The M₂ ribbons present the superior corrosion resistance because of the formation of amorphous phase. The i_corr, E_corr, E_pit, and E_pit – E_corr values of fully amorphous Al–Co–Ce–La metallic ribbons have a better trend of anti-corrosion performance compared to other crystalline and amorphous aluminum alloys.     

Can the theory of planned behavior explain patterns of health behavior change?

This article tested the ability of the theory of planned behavior (TPB) to predict patterns of behavior change associated with health screening. Attitudes, subjective norms, perceived behavioral control, and intentions were used to predict objective measures of attendance 1 month and 13 months later among participants who had never previously been screened (N?=?389). Findings showed that the TPB predicted attendance on each occasion and also predicted frequency of attendance. However, the model was unable to reliably distinguish among consistent attendees, participants who delayed attending, and participants who initially attended but relapsed. Thus, the TPB needs to be extended to understand behaviors that must be performed promptly and repeatedly for health benefits to accrue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microstructural Modeling of Pitting Corrosion in Steels Using an Arbitrary Lagrangian–Eulerian Method

Metallurgical and Materials Transactions A - Two microscale numerical models are developed in this work using a moving-mesh approach to investigate the growth process of pitting in different iron...     

Structure and properties of κ-carbides in duplex lightweight steels

Abstract

κ-Carbide in lightweight steel has been studied. Its thermal stability, crystal morphology, orientation relationship, degree of lattice misfit and mechanical properties have been measured experimentally. The mechanisms for the microstructural evolution of κ-carbide are considered based on the crystal structure, lattice misfit, element diffusivity and solute partition. The hard γ/κ grain and ductile α+κ grain provide an opportunity to develop lightweight steels with a desirable combination of mechanical properties.     

Marital behavior, parenting behavior, and multiple reports of preschoolers' behavior problems: Mediation or moderation?

Associations among positive and conflictual marital behavior and multiple reports of child behavior problems were examined in a community sample of 78 families with 3-year-old children. Maternal and paternal parenting behaviors were tested as potential mediators and moderators. Parents reported on child behavior problems and were observed during parent-child interaction and couple discussion in the presence of the child. Observers and preschool teachers also reported on child behavior problems. Less positive marital engagement and greater conflict were associated with observers' reports, but not with parents' or teachers' reports, of more behavior problems. Associations between marital behavior and child behavior problems were not explained by maternal or paternal behavior; stronger support was found for moderating effects of parenting. Also, positive marital engagement was a slightly better predictor of child behavior problems than was marital conflict. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of various sulfide stringer populations on the ductility of hot-rolled CMn steels

The effect of sulfide inclusions on anisotropy of axisymmetric and plane-strain fracture strain was investigated in three 0.1% C, 1.0% Mn steels containing 0.004, 0.021, or 0.028% S. The effect of the sulfide inclusions on axisymmetric and plane-strain fracture strain correlated with the projected area of inclusions per unit volume, A_r, or the mean local area fraction of inclusions on a plane perpendicular to the tensile direction regardless of tensile direction: transverse or through thickness. The magnitude of A_r was orientation dependent and was directly proportional to the volume fraction of inclusions and inversely proportional to the inclusion dimension parallel to the tensile direction. Dirichlet cell tessellation procedures were used to calculate local area fractions of inclusions, nearest-neighbor distances, and near-neighbors distances on longitudinal, transverse, and through-thickness planes. The mean local area fraction of inclusions was orientation dependent and was significantly larger than the total area fraction. The mean nearest-neighbor and near-neighbors distances were also dependent on orientation. The near-neighbors distances were incorporated into a simple anisotropic model of ductile fracture which gave good agreement with the observed fracture strains for both transverse and through-thickness specimens.     

Pitting corrosion behavior of cerium treated HSLA steel induced by sulfide inclusions in 3.5 wt% NaCl solution

Pitting corrosion behavior of Ce treated HSLA steels induced by sulfide inclusions in 3.5 wt% NaCl solution was investigated with potentiodynamic polarization and immersion corrosion test.The results show that Ce added steels exhibit better pitting corrosion resistance with lower corrosion current density and bigger pitting potential compared with steel without Ce,which is mainly attributed to optimized characteristics of spherical Ce-oxysulfide inclusions with less number density,smaller average size and lower pitting corrosion susceptibility.The spherical Ce₂O₂ S inclusions precipitated on the surface of CeAlO₃ inclusions in the Ce added steels induce pits with bigger opening mouth and shallow depth,reducing their tendency of extension to go deeper due to occlusion corrosion battery in the pitting holes.Furthermore,corrosion inhibitor Ce(OH)₃ generated by Ce₂O₂ S hydration can weaken electrochemical corrosion of the matrix micro-region around the pits.To avoid harmful bigger inclusions,Ce content in steels should be regulated within reasonable range,0.015 wt% Ce in present steels effectively modified inclusions to acquire the best pitting corrosion resistance of the steels.     

霉菌对超高强钢腐蚀行为的影响

采用扫描Kelvin探针测试技术,研究了300M钢、Aermet100钢与超高强不锈钢在黄曲霉、黑曲霉、球毛壳霉、绳状青霉和杂色曲霉组成的混合霉菌菌种作用下的腐蚀行为.通过扫描电镜结合能谱分析对霉菌在三种超高强钢上的生长进行了观察和分析.300M钢试样上霉菌呈现分散式堆积生长,数量逐渐增加;Aermet100钢试样上霉菌呈现分散式单个生长方式,数量逐渐增加;超高强不锈钢上霉菌呈现放射式网状生长方式,数量急剧增加,在钢表面形成一层生物膜.霉菌实验后,三种超高强钢表面都发生一定的腐蚀.300M钢腐蚀最严重,蚀坑宽而浅;Aermet100钢次之,蚀坑窄而深;超高强不锈钢的耐蚀性最好.扫描Kelvin探针测试结果表明,霉菌一定程度上能促进300M钢和Aermet100钢的腐蚀,而对超高强度不锈钢的腐蚀行为有一定抑制作用.     

Effects of rare earth on inclusions and corrosion resistance of 10PCuRE weathering steel

The types,morphologies and distributions of nonmetallic inclusions in Cu-P weathering steels with and without rare earth were analyzed through a quantitative image analyzer,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)attached to SEM.Solid-soluble content of rare earth in the steels was analyzed by non-aqua electroanalysis and ICP.The results showed that rare earth modified the types and the morphologies of inclusions in the weathering steels.The small spherical rare earth oxysulfides and rare earth sulphides replaced the elongated MnS inclusions in the RE weathering steels.The rare earth inclusions dispersedly distributed and most inclusions were smaller than 2 μm in size.The optimum content of RE was 0.0065%-0.016% for 10PCuRE weathering steels containing about0.002% oxygen and 0.004% sulfur.Solid-soluble content of rare earth in steels was(14-20)x 10-6,which can act as a micro-alloying element.The corrosion resistance of 10PCuRE weathering steels and Q235 were studied by dry-wet cyclic immersion test.Their corrosion rates were obtained respectively.The polarization curves and pitting corrosion behaviors of weathering steels with and without rare earth were measured by electrochemical methods.The corrosion resistance of Cu-P weathering steels was improved by adding an appropriate amount of rare earth.Less and fewer rare earth inclusions largely decreased pitting susceptibility and rate of pit propagation.The pitting potential and the resistance against pitting corrosion of the RE weathering steel were significantly improved due to the modification of rare earth to inclusions.     

海洋工程用钢的大气腐蚀与耐候钢的发展

综述了海洋工程用钢的大气腐蚀行为与耐候钢发展方面的研究,特别是近十余年来国内外的相关成果。首先介绍了钢大气腐蚀的电化学模型,并从耐候钢特殊的锈层结构与合金元素作用两方面论述了耐候钢的锈层保护机制;然后分析了环境因素,包括相对湿度与污染物、光照、锈层损伤等,对耐候钢大气腐蚀行为的影响;最后总结了耐候钢的发展历程以及晶粒尺寸与显微组织等非合金因素在耐候钢发展中的作用,可为新型耐候钢的设计与应用提供指导。     

Organic Metallogeny of Weathering Crust RE Deposit

ＯｒｇａｎｉｃＭｅｔａｌｏｇｅｎｙｏｆＷｅａｔｈｅｒｉｎｇＣｒｕｓｔＲＥＤｅｐｏｓｉｔＣｈｅｎＺｈｉｃｈｅｎｇ（陈志澄）（ＧｕａｎｇｄｏｎｇＣｏｌｅｇｅｏｆＰｈａｒｍａｃｙ，Ｇｕａｎｇｚｈｏｕ５１０２２４，Ｃｈｉｎａ）ＹｕＳｈｏｕｊｕｎ（俞受均金）...     

冰冻/解冻对低合金耐候钢大气腐蚀的影响

采用室内、室内+冰冻和户外三种不同环境的曝晒实验,研究了冰冻/解冻循环对两种耐候钢初期大气腐蚀行为的影响.利用失重实验和电化学方法评价了实验钢的耐腐蚀性能,用扫描电镜观察了锈层形貌,用能谱分析仪分析了合金元素在锈层中的分布.结果表明:低温、低湿环境促进致密锈层的形成,而温度、湿度较高的环境中形成的锈层致密度较低;冰冻/解冻循环导致非致密锈层内产生裂纹,其原因是疏松锈层中的孔洞中含有大量液态水,在液固相变时产生较大的应力,致使锈层开裂.致密锈层不含液态水,基本不受其影响.     

Effects of RE and N on Properties of Corrosion Resistance and Oxidation Resistance of Gray Cast Iron

ＩｔｉｓｗｅｌｋｎｏｗｎｔｈａｔｔｈｅｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｇｒａｙｃａｓｔｉｒｏｎｃａｎｂｅｉｍｐｒｏｖｅｄｂｙａｄｄｉｎｇｓｕｉｔａｂｌｅａｍｏｕｎｔｏｆＲＥａｎｄＮ．Ｔｏｈｉｇｈｃａｒｂｏｎｅｑｕｉｖａｌｅｎｔ（ＣＥ）ｇｒ...     

合金元素对高强耐候钢耐大气腐蚀行为的影响

为了考察氧含量对钢耐蚀性能的影响,冶炼了不同氧含量（质量分数在20×10⁻⁶～200×10⁻⁶范围）的碳钢和耐候钢. 通过扫描电镜夹杂物分析、极化实验、全浸实验等方法研究了钢中夹杂物类型、形态、数量、尺寸等随氧含量变化而变化的规律,以及对耐蚀性能的影响. 结果表明,随着钢中氧含量逐渐增大,钢中夹杂物由长条状MnS、Al₂O₃向颗粒状硅酸盐转变,夹杂物总数量、平均尺寸逐渐增大,譬如氧质量分数从20×10⁻⁶、60×10⁻⁶增大到195×10⁻⁶时,MnS数量占比从69.9%、23.7%减少到5.8%,硅酸盐数量占比从3.4%、54.9%增大到73.2%,夹杂物总面积分数从0.01%、0.04%增大至0.25%,等效圆直径从0.78 µm、1.15 µm增大至4.65 µm;点蚀电位呈升高趋势,整体升高40 mV左右;腐蚀速率先下降又回升,遵从三次函数变化规律,其中氧质量分数从20×10⁻⁶～30×10⁻⁶增大到60×10⁻⁶,碳钢腐蚀速率降低53%,耐候钢腐蚀速率降低24%,耐蚀性均提高. 分析认为,氧质量分数在20×10⁻⁶～100×10⁻⁶范围,易诱发腐蚀的长条状硫化物减少以及固溶氧增多而引起基体电位升高的共同作用导致在全浸腐蚀环境下钢的耐蚀性增强;氧质量分数在100×10⁻⁶～200×10⁻⁶范围,夹杂物的数量急剧增多使得钢的耐腐蚀性降低. 适当增大氧含量,可开发经济型耐腐蚀钢.

     

Comparative study on the corrosion behavior of low alloy steels in sulfuric acid solution

The corrosion behavior of a weathering steel SPA-C and two acid resistance steels( S-TEN1 and ND) in sulfuric acid solution was investigated by using potentiodynamic polarization and weight loss measurement techniques.Both potentiodynamic polarization and weight loss measurement tests indicated that corrosion resistance of these three alloy steels was as follows: ND ≈ S-TEN1 SPA-C.Surface analysis of the corroded samples conducted after the immersion test indicated that two layers were formed on the substrates,with the outer layer comprising Fe SO_4·H_2O and the inner layer mainly comprising iron oxides.The addition of Cu,Cr,and Sb refined the corrosion products and improved the adhesion ability between the rust layer and the substrate.     

海洋工程用钢的大气腐蚀与耐候钢的发展

综述了海洋工程用钢的大气腐蚀行为与耐候钢发展方面的研究,特别是近十余年来国内外的相关成果。首先介绍了钢大气腐蚀的电化学模型,并从耐候钢特殊的锈层结构与合金元素作用两方面论述了耐候钢的锈层保护机制;然后分析了环境因素,包括相对湿度与污染物、光照、锈层损伤等,对耐候钢大气腐蚀行为的影响;最后总结了耐候钢的发展历程以及晶粒尺寸与显微组织等非合金因素在耐候钢发展中的作用,可为新型耐候钢的设计与应用提供指导。