The effect of sodium benzoate and sodium 4-(phenylamino)benzenesulfonate on the corrosion behavior of low carbon steel

Abstract  The effect of sodium benzoate (SB) and sodium 4-(phenylamino)benzenesulfonate (SPABS) on the corrosion behavior of low carbon steel has been investigated using gravimetric method in the temperature range of 30–80 °C, velocity range of 1.44–2.02 m s⁻¹ and concentration range of 6.94 × 10⁻⁴ to 4.16 × 10⁻³ mol dm⁻³ SB and 3.69 × 10⁻⁴ to 2.06 × 10⁻³ mol dm⁻³ SPABS. Optimization of temperature, fluid velocity, and inhibitors concentration has been made. The obtained results indicate that the inhibition efficiency (w _IE %) at 1.56 m s⁻¹ is not in excess of 81.5% at 4.16 × 10⁻³ mol dm⁻³ SB and 84.4% at 2.06 × 10⁻³ mol dm⁻³ SPABS. The inhibitive performance of these compounds showed an improvement with increasing concentration up to critical values of SB and SPABS; beyond these concentrations no further effectiveness is observed. These inhibitors retard the anodic dissolution of low carbon steel by protective layer bonding on the metal surface. The adsorption of SB and SPABS on the low carbon steel surface was found to obey the Freundlich isotherm model. The FT-IR spectroscopy was used to analyze the surface adsorbed film. Graphical abstract  Low carbon steel corrosion in presence of sodium benzoate and sodium 4-(phenylamino)benzenesulfonate has been investigated. The adsorption mechanism obeyed Freundlich isotherm model. FT-IR was used to analyze the adsorbed film      

Determining the tensile response of materials at high temperature using DIC and the Virtual Fields Method

An experimental approach based on Digital Image Correlation (DIC) is successfully applied to predict the uniaxial stress-strain response of 304 stainless steel specimens subjected to nominally uniform temperatures ranging from room temperature to 900 °C. A portable induction heating device equipped with custom made water-cooled copper coils is used to heat the specimen. The induction heater is used in conjunction with a conventional tensile frame to enable high temperature tension experiments. A stereovision camera system equipped with appropriate band pass filters is employed to facilitate the study of full-field deformation response of the material at elevated temperatures. Using the temperature and load histories along with the full-field strain data, a Virtual Fields Method (VFM) based approach is implemented to identify constitutive parameters governing the plastic deformation of the material at high temperature conditions. Results from these experiments confirm that the proposed method can be used to measure the full field deformation of materials subjected to thermo-mechanical loading.     

Effect of Particle Conductivity on Fe-Si Composite Electrodeposition

Coatings containing Fe-Si or Si particles were electrodeposited on 3.0%（mass fraction） Si steel sheets. The surface morphology, the cross-section and the silicon content of coating have been investigated, respectively. It was found that the number of particles on the coating surface and cross-section significantly decreased with increasing silicon content in the applied particles, leading to a decrease of the silicon content of coatings. About 10.2% silicon content of coatings deposited with Fe-30%Si particles can be obtained, whereas that for Si particles was only 2.9% at a particle concentration of 100 g/L and current density of 2 A/dm2. This is mainly attributed to the conductivity of applied particles. High conductivity can promote the co-deposition of the particles. With increasing silicon content in the particles, their conductivity decreased sharply, resulting in the decrease of silicon content of coatings. Present work may initiate a new method to modify the particle content of the composite coatings via changing the conductivity of the particles during the composite electrodeposition. In this paper, a possible mechanism was proposed to explain the phenomena.     

P110钢CO2腐蚀产物膜的XPS分析

为了确定CO2腐蚀产物膜的组成及不同层次结构中成分和含量的差异,采用P110钢在高温高压腐蚀静态釜中制备CO2腐蚀产物膜,利用SEM观察了腐蚀产物膜的表面和断面形貌,结合XRD分析结果,通过XPS研究了两层结构膜的化学组成差异。结果表明,腐蚀产物膜断面呈现双层结构;膜层的主要成分是FeCO3,还有少量的CaCO3和铁的氧化物,但内层CaCO3较多且夹杂着Fe3C和单质Fe,外层氧化物稍多;通过内外层Ca^2＋含量差异推断出内层腐蚀膜优先形成。     

混合物理化学气相沉积法制备不锈钢衬底MgB2超导厚膜样品的韧度研究

我们用混合物理化学气相沉积法(HPCVD)制备了一批不锈钢衬底的MgB2超导厚膜样品,厚度在10～30μm间,Tc(onset)是37.8～37.2K,超导转变宽度ΔT在1.2K左右,是(101)方向织构的致密厚膜,并有少许MgO杂相.对样品进行弯折研究,随着弯曲角度的增加,膜面出现不同程度的条状裂纹,但仍能保持膜面的基本完整;虽然样品的超导起始转变温度降低、转变温区变宽,性能有所下降,但超导特性仍能保持在一个很好的水平上.这个结果表明了采用HPCVD方法制备不锈钢衬底带材将会很好地克服MgB2超导膜由于硬脆的性质而无法绕制磁体的问题,有着十分重要的应用意义.     

Multiaxial cyclic deformation and non-proportional hardening employing discriminating load paths

Some novel discriminating multiaxial cyclic strain paths with incremental and random sequences were used to investigate cyclic deformation behavior of materials with low and high sensitivity to non-proportional loadings. Tubular specimens made of 1050 QT steel with no non-proportional hardening and 304L stainless steel with significant non-proportional hardening were used. 1050 QT steel was found to exhibit very similar behavior under various multiaxial loading paths, whereas significant effects of loading sequence were observed for 304L stainless steel. In-phase cycles with a random sequence of axial-torsion cycles on an equivalent strain circle were found to cause cyclic hardening levels similar to 90° out-of-phase loading of 304L stainless steel. In contrast, straining with a small increment of axial-torsion on an equivalent strain circle results in higher stress than for in-phase loading of 304L stainless steel, but the level of hardening is lower than for 90° out-of-phase loading. Tanaka’s non-proportionality parameter coupled with a Armstrong–Fredrick incremental plasticity model, and Kanazawa et al.’s empirical formulation as a representative of such empirical models were used to predict the stabilized stress response of the two materials under variable amplitude axial-torsion strain paths. Consistent results between experimental observations and predictions were obtained by employing the Tanaka’s non-proportionality parameter. In contrast, the empirical model resulted in significant over-prediction of stresses for 304L stainless steel.     

Ti_3SiC_2/PM304摩擦副的高温摩擦学性能

本文考察了Ti3SiC2/PM304摩擦副从室温到630℃范围的摩擦磨损性能,并与Ni-Cr合金/PM304摩擦副的摩擦磨损性能进行了对比.结果表明:Ti3SiC2/PM304摩擦副具有比Ni-Cr合金/PM304摩擦副更好的摩擦磨损性能,特别是在400～630℃的温度范围内,Ti3SiC2/PM304摩擦副具有优异的摩擦磨损性能.从室温到300℃,Ti3SiC2/PM304摩擦副的磨损机制为Ti3SiC2晶粒拔出、脱落后与转移的PM304形成机械混合层,随着环境温度的升高机械混合作用加强.在400～630℃范围内,摩擦界面的机械混合作用受到显著抑制,在Ti3SiC2磨损表面形成富集银的转移润滑膜,而转移润滑膜的连续性对摩擦副的摩擦磨损性能影响较大.     

激光诱导等离子体光谱法检测合金钢组分的实验研究

激光诱导击穿光谱技术(LIBS)具有无需样品制备,原位快速分析,可进行实时控制的特点使其在钢铁冶炼控制中具有巨大的实际应用价值。本文以波长为1 064 nm的Nd∶YAG调Q固体激光器为激发光源,CCD为探测器,高合金钢GBW01605—01609系列为样品,在建立的LIBS实验装置上研究激光与合金钢之间的相互作用。系统地研究了观测距离、激光能量对高合金钢样品中激光诱导击穿谱特性的影响,并分析了LIBS信号的时间分辨特性,确定了将LIBS用于合金钢微量元素定量分析时的最佳实验条件。     

Strain rate and cold rolling dependence of tensile strength and ductility in high nitrogen nickel-free austenitic stainless steel

The tensile strength and ductility of a high nitrogen nickel-free austenitic stainless steel with solution and cold rolling treatment were investigated by performing tensile tests at different strain rates and at room temperature. The tensile tests demonstrated that this steel exhibits a significant strain rate and cold rolling dependence of the tensile strength and ductility.With the increase of the strain rate from 10~(-4)s~(-1)to 1 s~(-1), the yield strength and ultimate tensile strength increase and the uniform elongation and total elongation decrease. The analysis of the double logarithmic stress–strain curves showed that this steel exhibits a two-stage strain hardening behavior, which can be well examined and analyzed by using the Ludwigson equation. The strain hardening exponents at low and high strain regions(n_2and n_1) and the transition strain(εL) decrease with increasing strain rate and the increase of cold rolling RA. Based on the analysis results of the stress–strain curves, the transmission electron microscopy characterization of the microstructure and the scanning electron microscopy observation of the deformation surfaces, the significant strain rate and cold rolling dependence of the strength and ductility of this steel were discussed and connected with the variation in the work hardening and dislocation activity with strain rate and cold rolling.