Marriage Fraud

This Article examines the astonishing array of doctrines used to determine what constitutes marriage fraud. It begins by locating the traditional nineteenth-century annulment-by-fraud doctrine within the realm of contract fraud, observing that in the family law context fraudulent marriages were voidable solely at the option of the injured party. The Article then explains how, in the twentieth century, a massive expansion of public benefits tied to marriage prompted new marriage fraud doctrines to develop in various areas of the law, shifting the concept of the injured party from the defrauded spouse to the public at large. It proposes a framework for understanding these new doctrines by demonstrating that courts apply different tests for finding fraud depending on the value of the benefit sought compared to the cost to the individual of using marriage to obtain it. Furthermore, the Article argues that marriage is an ineffective means for distributing public benefits that serve specific objectives; in other words, marriage is being asked to do too much work. As a possible response to this problem, the Article concludes that lawmakers could disaggregate the components of marriage to which they attach public benefits. This would improve the efficacy of public benefits distribution without entirely dismantling the institution of marriage or jeopardizing the stability that it may provide to societ

A New Alloy for High Performance Valve Steel for High Efficiency Compressors

In 2018 the International Energy Association IEA reported that air conditioning will be a major contributor for future electricity consumption (Birol, F. 2018). As recently seen in China, tougher legislation on energy efficiency for air conditioning and refrigeration is being introduced all the time. It is therefore crucial that new compressor models perform at the highest levels in terms of efficiency to reduce global energy consumption. The prerequisites to fulfill this legislation vary for the different applications such as rotary, reciprocating, scroll and linear compressors. However, to succeed in developing more energy efficient compressors, the ability to improve the performance of the flapper valves will play an important role. Furthermore, the current commercial alloys available for flapper valves may not be sufficient to meet these increasing demands. In the past, to improve the material fatigue properties, the development of high-performance flapper valve material has been focused around optimizing the metallurgical cleanliness, microstructure, surface finish and mechanical properties. Now research has been completed to develop a new alloy composition aiming to develop a material with further improved fatigue properties for flapper valve applications. The results from internal and external testing of the new alloy show significantly improved fatigue properties. Within this paper, some of the critical properties of the new alloy are presented and the test results are compared with other existing flapper valve steels on the market

Інформаційна система моделювання і обробки сейсмічних сигналів

Austenitic stainless steel grade UNS S31035 (Sandvik Sanicro® 25) has been developed for use in super-heaters and reheaters in the next generation of A-USC power plants. This new grade shows very good resistances to steam oxidation and hot corrosion, and higher creep rupture strength than other austenitic stainless steels available today. This makes it an interesting alternative for super-heaters and reheaters in future high-efficient coal fired boilers. This paper will mainly focus on the study of the creep and LCF behavior of the material at temperatures from 600 °C to 750 °C by using TEM and ECCI. The mechanisms at different temperatures and loading conditions have been identified. The interactions between dislocations and precipitates and their contribution to the creep rupture strength have been discussed. In this paper, different models have been used to evaluate the long-term creep behavior of the grade. A creep rupture strength near 100 MPa at 700 °C for 100 000 h has been predicted

Selection of Flapper Valve Steel for High Efficient Compressor

Due to the environmental, energy saving and economic requirements, development of very high efficient compressors is of great importance. Consequently, flapper valve material becomes a critical issue and a limiting factor for the development of compressor. This paper provides a discussion on the material selection of the flapper valve for the compressors with very high efficiency, based mainly on a basic research on the mechanisms of impact fatigue and a FEM simulation on the formation of stress concentration in the flapper valve during the impact process. Impact fatigue initiation is caused by the initial impact stress, but the fatigue crack propagation is caused by a wavy stress propagation. This causes the formation of secondary cracks at the stress concentration points where two stress waves have the same phase. The results indicate that the flapper valve materials for the very high efficient compressors should have both high impact fatigue strength for the initial stress, and high stress damping capacity to reduce the crack propagation rate. Most recent developed flapper valve steel, Sandvik Hiflex™, shows both higher impact fatigue strength and higher damping capacity comparing with other commercial flapper valve steels available. This flapper valve steel material has successfully been used in the newly developed high efficient compressors recently. Some case stories have been discussed

Secondary Hardening Behavior in Super Duplex Stainless Steels during LCF in Dynamic Strain Ageing Regime

Cyclic deformation behaviors in five modified duplex stainless steel S32705 grades have been studied at 20 °C, 200 °C, 250° and 350 °C. The influence of temperature and nitrogen concentration on the occurrence of the second hardening phenomenon, in the stress response curve was focused. An increase in nitrogen concentration can have a positive effect on dynamic strain ageing by increasing the first hardening and also the second hardening behavior during cyclic deformation. Furthermore, an increase in nitrogen concentration in the super duplex stainless steel increases the fatigue life in the strain ageing temperature range. The occurrence of strain ageing in duplex stainless steel has greatly changed dislocation structures. The formation of irreversible dislocation structures and stacking faults can contribute to the formation of second hardening in the stress response curve

Secondary Hardening Behavior in Super Duplex Stainless Steels during LCF in Dynamic Strain Ageing Regime

Cyclic deformation behaviors in five modified duplex stainless steel S32705 grades have been studied at 20 °C, 200 °C, 250° and 350 °C. The influence of temperature and nitrogen concentration on the occurrence of the second hardening phenomenon, in the stress response curve was focused. An increase in nitrogen concentration can have a positive effect on dynamic strain ageing by increasing the first hardening and also the second hardening behavior during cyclic deformation. Furthermore, an increase in nitrogen concentration in the super duplex stainless steel increases the fatigue life in the strain ageing temperature range. The occurrence of strain ageing in duplex stainless steel has greatly changed dislocation structures. The formation of irreversible dislocation structures and stacking faults can contribute to the formation of second hardening in the stress response curve

Structural Stability of Sandvik 3R60™ After 240 131 Hours Ageing and Creep Test at 700 °C

Sandvik 3R60™ is an AISI 316/316L type of stainless steel. In this paper, the structural stability of the material under long-term ageing or creep test has been studied. The material had been creep tested with a stress of 45 MPa at 700 °C. The predicted rupture time for the creep specimen was about 100,000 h; however, the specimen broke first after 240,131 h. The oxidation behavior and structural stability in both aged and creep-tested samples were studied using SEM/EDS, EBSD and ECCI techniques. Thin oxide layers near the sample surface are mainly spinel oxides and eskolaite (Cr2O3). Sigma phase, χ-phase, Eta phase, M23C6 and Cr2N have been observed in the matrix of the samples. In the crept sample, the amount of sigma phase has increased, so has Eta phase and χ-phase as well. Thermo-Calc evaluation can reasonably predict precipitation of sigma phase, Eta phase and M23C6, but not χ-phase and Cr2N phases. Creep crack initiation behavior has been studied. It is mainly noticed to start at surface oxide layer or coarse sigma particles at grain boundary or triple point. Additionally, it is also observed that the presence of a thin Cr2O3 layer between the oxide and matrix along with discontinuous sigma phase distribution at grain boundary that will reduce the risk for creep crack initiation. Further, the crack propagation behavior has also been discussed