The application of magnetic structural phase analysis for the diagnostics of the State of a 08X18H10T Steel-Ct3 Steel composite material and its components that were subjected to plastic deformation

The use of composite, in particular, multilayer materials, is one way to decrease the specific quantity of metal in an item and to increase its service characteristics. To develop methods for the diagnostic of the state of such composite materials and their components, the effect of cold rolling on the structure, magnetic, and mechanical properties of a two-ply composite material and its separate components was studied; the material was prepared by explosion welding of austenitic corrosion-resistant and low-carbon steels. It was shown that magnetic characteristics can be used for estimating the degree of deformation by rolling, phase composition, and mechanical properties of both two-ply 08X18H10T Steel-C^t3 Steel composite material as a whole and its separate components.     

Magnetic estimation of stresses applied to a two-layer steel CT3-steel 08X18H10T composite material during elastoplastic deformation by uniaxial tension

The effect of uniaxial-tension stresses on the structure and physicomechanical properties of a two-layer Steel C_T3-Steel 08X18H10T composite material that underwent preliminary rolling and steels that contain this material was studied. Within the practically important elastic-deformation region, the coercive force, maximum magnetic permeability, and residual inductance of the materials under study were found to exhibit unambiguous behavior and can be used for estimating changes in the stressed-deformed state of articles that are made from the composite material under conditions of uniaxial tension. We demonstrated that it is possible to use the heights and positions of peaks in the field dependence of the magnetic permeability for determining the degree of elastoplastic deformation by uniaxial tension of both the composite material as a whole and the components that comprise the material for estimating the applied stresses.     

X80高屈强比管线钢性能分析与管道安全性预测

测出X80等5种材料常规机械性能及名义应力屈强比σs/σb和真实应力屈强比Ss/Sb。比较发现Ss/Sb较σs/σb小13%,表明高强度、高屈强比X80钢屈服后塑性变形裕度仍较大。还测出材料静力韧度、冲击韧性及断裂δR阻力曲线,并应用于X80钢管线安全性预测,可以认为,高屈强比对结构安全性的影响并非如通常认为的那么严重。最后讨论了屈强比对硬化指数n的影响。     

Cold Strength and Failure of 3D-Printed Metals

Russian Engineering Research - The cold strength and low-temperature failure of 3D-printed 08Г2С and 07Х25Н13 steels are considered. Specifically, the metals are produced by...     

抗H2S应力腐蚀开裂热交换器专用钢 (08Cr2Al Mo钢)的研究

在抗H     

压缩天然气气瓶临界裂纹尺寸的研究

以压缩天然气气瓶用钢4130X钢为材料，实测了高浓度和中等浓度硫化氢腐蚀溶液中材料的临界应力强度因子，得出压缩天然气气瓶在高浓度和中等浓度硫化氢溶液中的临界裂纹尺寸，为保证压缩天然气气瓶安全运行进行的裂纹评定提供了实验依据。     

Geometric accuracy of incremental sheet forming for TRIP590

TRIP steels have both high strength and good ductility, and they are typically used in automotive industry for the purpose of safety and energy saving. Deforming TRIP steel by ISF is practically valuable, but the application is significantly restricted by its geometric accuracy. At present, there is not enough research on geometric accuracy for TRIP steels. In this study, we explored the geometric accuracy of ISF for TRIP590 by referring to 1060Al steel and 08F steel. We found that the accuracy of TRIP590 steel was the lowest, which was because of the phase transformation of the material which occurred during deformation. To verify this, X-ray diffraction was employed to figure out the volume fraction of retained austenite. The results have shown that there is always TRIP effect during ISF process, and the relationship between natural logarithm of austenite volume fraction and the equivalent strain is negative linear. Lastly, it is proved that multiple reverse compensations could improve the geometric accuracy for TRIP steels.     

Elevated temperature erosion of steels

The elevated temperature erosion behavior of several commercial ferritic and austenitic steels was determined over a range of temperatures from room temperature to 900 °C. It was determined that all the steels had constant or decreasing erosion rates as the test temperature was increased until a temperature was reached where a marked increase in erosion rate began to occur with temperature. Austenitic steels were determined to have lower erosion rates than ferritic steels and their hardness had no correlation with their erosion rate. All the steels tested eroded by the platelet mechanism of erosion.     

多轴低周疲劳载荷下应用von Mises及Tresca准则的寿命预测研究

在应变控制比例与非比例载荷条件下,应用ｖｏｎＭｉｓｅｓ及Ｔｒｅｓｃａ屈服函数分别结合Ｍｒｏｚ多表面强化模型研究了０８Ｘ１８Ｈ１０Ｔ不锈钢材料的低周循环特性。给出０８Ｘ１８Ｈ１０Ｔ不锈钢在柢周多轴应变控制加载条件下用能量理论进行了寿命预测及其试验验证。应用Ｔｒｅｓｃａ屈服函数结合Ｍｒｏｚ多表面塑性流动理论进行寿命预测能够很好地描述试验结果,应用ｖｏｎ Ｍｉｓｅｓ屈服函数结合Ｍｒｏｚ多表面塑性流动理论在工程计算中进行寿命预测,简便易行。     

Effect of ion-beam nitriding on structure, phase state, and tribological behavior of efficient thermal spray coatings deposited from various classes of rod steels

Thermal spray coatings produced by the hypersonic spraying of ferritic (Sv-08G2S), martensitic (40Kh13), and austenitic (06Kh19N9T) rod steels and treated by intensive nitrogen ion flows were studied. Metallographic and X-ray diffraction structural analyses of modified coatings were carried out, as well as their microhardness and tribological characteristics were determined. It has been shown that ion-beam treatment leads to an increase in the wear resistance of coatings from the ferritic steel by 2–80 times, those from the martensitic steel by 2–13 times, and those from the austenitic steel by 10–35 times. Based on the results obtained, temperature conditions for ion-beam nitriding that ensure the best tribological characteristics of the coatings deposited from various classes of rod steels have been selected.     

Using Kelvin probe force microscopy for controlling the phase composition of austenite–martensite chromium–nickel steel

The effectiveness of Kelvin probe force microscopy, which is one of the scanning probe techniques, is demonstrated for assessing plastic-deformation induced changes in the phase composition of 08Kh21N6M2T austenite–martensite chromium–nickel steel. Changes in the numerical values of surface potentials of different phase components of two- and three-phase stainless steels versus sample deformation extent have been established. Dependence of surface electric potentials as measured with Kelvin probe force microscopy on the presence and amount of newly formed deformationmartensite phase has been discovered.     

Variations in several acoustic emission parameters during testing of low-carbon steel specimens

The acoustic emissions that are formed during tension of specimens made from low-carbon steels is investigated. Interpretation of the experimental data is made from the point of view of real tests of engineering objects made from low-carbon steels in order to analyze the correlation of informative parameters with the deflected mode of a metal.     

Experimental assessment of droplet impact erosion resistance of steam turbine blade materials

The droplet impact erosion resistance of five different but highly relevant steam turbine blade materials is investigated with the help of an erosion test rig. The rig adapts wetness and droplet impact speed conditions in the last stages of condensing steam turbines in such a way that the material degradation is greatly accelerated in order to establish monotonic saturating material loss gradients—ideally within a testing time interval of 50 h. Repeatability and reproducibility of the evaluation method is ensured to facilitate the representative ranking of materials based on droplet impact erosion resistance being a key material property for durable steam turbine blade designs.A selection of three blade steels (X20Cr13, a steel similar to X5CrNiMoCuNb 14-5, X5CrNiCuNb 16-4) and one titanium alloy (Ti6Al4V) is tested and analysed. Additionally, X5CrNiCuNb 16-4 in a laser-hardened condition is investigated. Besides the influence of droplet impact speed and droplet impact angle on erosion, the generated surface jaggedness, the level of material degradation as well as the material loss gradients are discussed and utilised for further deductions. Among the high yield strength blade steels, the laser-hardened X5CrNiCuNb 16-4 exhibits the best erosion resistance while Ti6Al4V exhibits a higher erosion resistance than all the steel alloys tested.Finally, a simplified but functional model is inferred from the test data to estimate the droplet impact erosion resistance of alternative steel and titanium blade materials relative to the materials discussed in this text.     

Effect of laser treatment on the case structure of constructional steels and their wear resistance

Investigations of the case structure and wear resistance of constructional steels 40X, 20X, 45, and IIIX 15 hardened by laser treatment are carried out. The damage of the contact surface of friction pairs hardened by a laser beam is demonstrated to determine the structure-phase transitions which are implemented at high rates of heating and cooling. The degree of hardening depends on the nature of the metal, the preheat treatment, the structure state, and the geometric parameters of the radiation exposure.     

Coercive force of ferromagnetic steels under the biaxial symmetrical tension of a material

Patterns of coercive force variations of Ct.3 and X70 ferromagnetic steels under biaxial symmetrical tension within both elastic and plastic ranges of deformation were studied using X-shaped specimens. It was shown that the coercive force of isotropic polycrystalline materials increased during plastic deformation under biaxial symmetrical tension and was proportional to applied stresses (loads). Plastic deformation of materials with high initial coercive-force anisotropy along the principal directions (X70 steel) leads to an abrupt decrease in anisotropy and subsequent alternation of its sign. The patterns of a material’s coercive force behavior allow the coercive force to be used for estimating the stress-strain state (from both an increase in the coercive force and its variations during loading as compared to that of the initial material) of articles made from the studied steels under biaxial symmetrical tensile deformation.     

Influence of the surface layer structure on the interaction character of friction pairs formed by X155CrMo12-1, 41Gr4, and 35GrMnSi4 steels with CuAl9Fe4 bronze

A comparative analysis of tribotechnical characteristics of friction pairs of X155CrMo12-1, 41Gr4, and 35GrMnSi4 steels with a counterbody of CuAl9Fe4 bronze, which were tested under conditions corresponding to operation of friction units of axial-piston pumps, is carried out. Practical recommendations on the substitution of 35GrMnSi4 structural steel with the diffusion surface hardening for X155CrMo12-1 high-alloy steel when making the supporting and distributor disks of hydraulic pumps are formulated.     

高钢级输气管线钢的止裂设计判据研究

对国产X70,X80管线钢,分别进行了夏比冲击试验(CVN)和单拉伸试验,测量得到管线钢的CVN和力学性能指标。基于管线钢CVN和力学性能指标的实测值,分析了管道断裂扩展速度的影响因素。基于速度准则,由编制程序计算的减压波速曲线联合管道断裂扩展速度计算公式,进行了实际工程的止裂设计应用。     

屈强比升高对管线钢使用安全性的影响

为了研究屈强比升高对管线钢使用安全性的影响,测试了5种常用钢材的工程应力及真应力-真应变曲线,计算了名义屈强比、真实屈强比和静力韧度。结果表明:随着钢强度级别的升高,名义屈强比会不断升高,材料的塑性指标有下降的趋势;真实屈强比在表征材料塑性变形余量方面比名义屈强比更客观,名义屈强比放大了屈强比升高的安全隐患;X80管线钢的屈强比虽然较高,但其抵抗变形的能力并未降低;对高强度管线钢规定过低的屈强比,会造成不必要的浪费。     

Medium carbon steel alloy design for wear applications

The fracture characteristics of steels are strongly influenced by martensite substructure, retained austenite stability, and morphology. Attractive strength-toughness properties have been attained with Fe-Cr-C-Mn alloys. These alloys, when tested under sliding wear conditions, also exhibit good wear resistance which compares favorably with that of commercial wear-resistant alloys. The most significant finding is an apparently strong correlation between sliding wear resistance and retained austenite, which in turn appears to correlate with Charpy impact properties. Little correlation was observed between hardness and wear resistance for the experimental steels.     

Estimating the magnetization of a long construction

A method for nondestructive evaluation of the magnetization of a long metallic construction using a closed magnetic circuit was proposed and tested for 40X and 09??2C steels. The method, which was developed for estimating the magnetization of long constructions, assumes the formation of two oppositely directed local-magnetization zones in it and measurement of the their stray fields.