Criteria of Material Failure in Relation to Hydrogen Saturation

2021 ◽  
Vol 316 ◽  
pp. 484-489
Author(s):  
Vladimir I. Mironov ◽  
Igor G. Emel'yanov ◽  
Olga A. Lukashuk
Keyword(s):  
Hydrogen Embrittlement ◽  
Ultimate Strength ◽  
Working Conditions ◽  
Chemical Industry ◽  
Material Failure ◽  
Metallic Materials ◽  
Hydrogen Degradation ◽  
Metallic Structures ◽  
Hydrogen Corrosion ◽  
Hydrogen Saturation

A steadily rising interest which specialists in various fields show towards the problem of hydrogen affecting metallic materials and causing their failure is connected to all-increasing requirements set on the durability of machines and equipment in operation. Metallic structures are most often surrounded by such environment which contains hydrogenous components or hydrogen itself (in chemical industry, power engineering, etc). And it leads to various types of degradation in metals (hydrogen embrittlement, hydrogen corrosion, and so on), which, in its turn, could cause catastrophic results. Ultimate strength is considered to be a representative parameter of the process of hydrogen degradation in steels. The authors cite the results of testing conducted on hydrogen-saturated specimens made of A516-55 steel which register a significant decrease in the ultimate strength. It is proposed to use a diagram which describes a fall in metal strength and transition of structural materials into their brittle states following an increase in hydrogen concentration. Discussion is made on criteria for hydrogen-saturated materials of metallic structures failing when a momentary overload occurs under default working conditions.

scholarly journals Comparison of resistance to damage of unalloyed carbon steels under the influence of hydrogen

2018 ◽  
Vol 174 ◽  
pp. 01015
Author(s):  
Izabela Pietkun-Greber
Keyword(s):  
Construction Material ◽  
Carbon Steels ◽  
Operating Conditions ◽  
Nacl Solution ◽  
Hydrogen Degradation ◽  
Significant Deterioration ◽  
Hydrogen Saturation ◽  
The Impact ◽  
Corrosive Resistance ◽  
Unalloyed Steel

One of the most commonly used construction material in industry is unalloyed steel S235 and S355. These types of steel are used for construction of ships, bridges, coastal construction, welded tanks, and in buildings. Due to the operating conditions, these types of steel may undergo hydrogen degradation in the process of manufacturing of welded structures or when operating the structures. This paper presents the results of study into resistance of selected types of non-alloy structural steels to hydrogen degradation. Tests were carried out to determine changes in mechanical properties in the static trials of stretching without hydrogen, and after saturation with hydrogen. Parallel fractographic and electrochemical studies were carried out. Hydrogen saturation was carried out at the time from 3. up to 24. hours in a solution of 0.1N H2SO4 with the addition of 2 mg/dm3 arsenic oxide (III) at an electric current density of 20 mA/cm2. The results of the tests have shown that the impact of hydrogen on the tested steels S235JR and S355J2 leads to a significant deterioration in their mechanical and electrochemical properties. At comparable concentrations of hydrogen, steel S235JR is less susceptible to hydrogen degradation and has greater corrosive resistance measured in 3% NaCl solution, in comparison with steel S355J2.

Impact of Trade Unions on Productivity: A Study of the Indian Chemical Industry

1989 ◽  
Vol 14 (2) ◽  
pp. 13-18 ◽  
Author(s):  
Ramjas
Keyword(s):  
Working Conditions ◽  
Chemical Industry ◽  
Trade Unions ◽  
Political Climate ◽  
Trade Unionism ◽  
Indian Context ◽  
Increase Productivity ◽  
Managerial Response

In this article, Ramjas analyses the extent to which trade unions affect productivity in the Indian context. Based on an analysis of data (1960-1980) from the Indian chemical industry, the author finds that trade unionism brings down productivity. He suggests that the potential of trade unions to increase productivity has not been fully exploited owing to factors such as managerial response to unionism, working conditions, wages of workers, and the socio-political climate in the country.

Architectured Multi-Metallic Structures Prepared by Cold Dynamic Spray Deposition

2019 ◽  
Vol 810 ◽  
pp. 107-112
Author(s):  
Ivo Dlouhý ◽  
Lukas Rehorek ◽  
Hanuš Seiner ◽  
Jan Čížek ◽  
Filip Šiška
Keyword(s):  
Spray Deposition ◽  
Strength Properties ◽  
Metallic Materials ◽  
Metallic Structures ◽  
Ti Alloys ◽  
Spatial Ordering ◽  
Beam Patterns ◽  
Theoretical Considerations ◽  
Single Material ◽  
Al Matrix

The architectured metallic materials are a class of composite materials that combines two or more metals/alloys with a specific spatial ordering (architecture). The main goal behind the preparation of such materials is to obtain properties that are not achievable by a single material. The internal architecture thus creates an extra degree of freedom in materials design. Based on theoretical considerations three aluminum alloy structures containing square, triangle and sinusoidal iron beam patterns have been prepared by a cold spray deposition technique. Strength properties difference and good bonding of the reinforcing Fe structure to the Al matrix has been found to be important for effective improvement of final properties. Incorporating about 30 vol. % structured iron beams into the Al matrix resulted in a macroscopic performance of the architectured multimaterial similar to Ti alloys.

scholarly journals Grain-boundary engineering markedly reduces susceptibility to intergranular hydrogen embrittlement in metallic materials

2009 ◽  
Vol 57 (14) ◽  
pp. 4148-4157 ◽  
Author(s):  
S. Bechtle ◽  
M. Kumar ◽  
B.P. Somerday ◽  
M.E. Launey ◽  
R.O. Ritchie
Keyword(s):  
Hydrogen Embrittlement ◽  
Grain Boundary ◽  
Metallic Materials ◽  
Grain Boundary Engineering

Plastic deformation mechanisms in nanocrystalline metallic materials

2013 ◽  
Vol 22 (3-4) ◽  
pp. 81-88 ◽  
Author(s):  
Ilya A. Ovid’ko
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Grain Boundaries ◽  
Computer Simulations ◽  
Theoretical Models ◽  
Deformation Mechanisms ◽  
Dislocation Slip ◽  
Metallic Materials ◽  
Metallic Structures ◽  
Mechanisms Of Plastic Deformation

AbstractThis article discusses the experiments, computer simulations, and theoretical models addressing the conventional and specific mechanisms of plastic deformation in nanocrystalline metallic materials. Particular attention is devoted to the competition between lattice dislocation slip and specific deformation mechanisms mediated by grain boundaries as well as its sensitivity to grain size and other parameters of nanocrystalline metallic structures.

scholarly journals Considerations on the Use of Explosive Substances for the Destruction of Metallic Structures

2019 ◽  
Vol 24 (2) ◽  
pp. 139-144
Author(s):  
Florin Ilie ◽  
Mircea Vladu ◽  
Gabriela Mihăilă-Lică ◽  
Bogdan-Mihai Georgescu
Keyword(s):  
Public Order ◽  
Metallic Materials ◽  
Metallic Elements ◽  
Metallic Structure ◽  
Destructive Effect ◽  
Metallic Structures ◽  
Degree Of Risk ◽  
Explosive Substance ◽  
High Degree

Abstract Incidents with IEDs containing metallic elements in the vicinity of the explosive substance pose a high degree of risk, endangering safety, peace and public order. In such situations, the methods and procedures applied as response by the authorities are cumbersome and risky, given the improvised nature of these incidents. In this paper we intend to analyze the destructive effect of explosive substances on certain metallic materials and we focus on a U-shaped metallic structure.

scholarly journals Morbidity patterns of workers employed in pharmaceutical-chemical industry

2007 ◽  
Vol 135 (3-4) ◽  
pp. 184-190 ◽  
Author(s):  
Aleksandar Milovanovic ◽  
Branko Jakovljevic ◽  
Jovica Milovanovic ◽  
Katarina Paunovic ◽  
Dragan Ilic ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Working Conditions ◽  
Chemical Industry ◽  
Control Group ◽  
Pharmaceutical Chemical ◽  
Work Activity ◽  
Pharmaceutical Chemical Industry ◽  
Exposed Workers ◽  
Occupationally Exposed ◽  
Physical Examinations

Introduction. Work in pharmaceutical-chemical industry is characterized by exposure to numerous hazards, both physical (microclimate, illumination, noise) and chemical (organic solvents). Organic solvents can cause damage to many organic systems and have carcinogenic, teratogenic and mutagenic effects. Objective. The aim of this study was to analyze patterns of chronic morbidity of workers employed in pharmaceuticalchemical industry during 2002. Method. The study was conducted in the pharmaceutical- chemical industry "Zdravlje" Leskovac in 2002. A total of 143 workers in workplaces with special working conditions - exposed to chemical hazards as well as 40 workers from control group took part in the study. The physical examinations of the participants were performed at the Department of Occupational Health in Health Center, Leskovac. Results. Heart diseases were the most frequent both among exposed workers (17.8%) and in control group (33.3%). Respiratory diseases were at the second place (16.9% in the exposed group, and 7.4% in control group). Arterial hypertension was diagnosed in 14.7% workers occupationally exposed to hazards, and in 12.5% workers from control group (p>0.05). Chronic bronchitis was diagnosed in 17.5% of the exposed workers and in only 5.0% of controls (p>0.05). The highest prevalence of diseases in both groups was observed among workers aged 40-49 years, with 20-29 years of exposure working time. 73.4% of the exposed workers and 85% of control workers were capable of work (p>0.05). Conclusion. Workers occupationally exposed to hazards in pharmaceutical-chemical industry have higher prevalence of various diseases compared to non-exposed workers, which can be the result of work, working conditions and work activity. Preventive measures should be directed towards the decrease of occupational hazards and unfavorable working conditions and increase of work protection. Regular physical examinations of workers are of prime importance for the prevention of occupational morbidity, traumatism and invalidity. .

Research on Preparing Recycling Boards by Using Non-Metallic Materials of Obsolete Printed Circuit Boards

2013 ◽  
Vol 743 ◽  
pp. 199-202
Author(s):  
Yan Chao Zhang ◽  
Bo Liu ◽  
Wei Jing Gao ◽  
Jia Hui Zhu ◽  
Wu Biao Duan ◽  
...  
Keyword(s):  
Working Conditions ◽  
Noble Metals ◽  
Printed Circuit Boards ◽  
Hydraulic Pressure ◽  
Metallic Materials ◽  
Circuit Boards ◽  
Optimum Conditions ◽  
Printed Circuit ◽  
Pressing Time ◽  
The Press

The printed circuit boards (PCBs) are the basis of all electrical and electronic equipment (EEE) and thus are one of the most important branches of WEEE stream. Present researches mainly concentrate on the processes of reusing noble metals and copper, and a great deal of nonmetals in PCBs are disposed by combustion or filling, which may cause secondary pollution and resource-wasting. So in this paper, we study how nonmetals are used to produce recycling boards through adding different adhesives, and obtain the best formulation and working conditions. The best formulation is that the binder is Polypropylene (less than 20%), additive are methenamine (little) and stearic acid (little). Effects of working conditions on the molding results are investigated. The results show that the optimum conditions for hydraulic pressure machine are the temperatures of 160 °C, warming and pressing time of 10 minutes and the press of 30MPa.

scholarly journals Maximum Allowable Service Pressure for Steel Pipes Used for Transport of Hydrogen Pure or Blended with Natural Gas

2020 ◽  
pp. 61-82
Author(s):  
Jamie Kuk Anak Mijim ◽  
Guy Pluvinage
Keyword(s):  
Natural Gas ◽  
Hydrogen Embrittlement ◽  
Operating Pressure ◽  
Metallic Materials ◽  
Gas Network ◽  
Steel Pipes ◽  
Natural Gas Network ◽  
Over Time

The addition of hydrogen in natural gas could have an impact on the degradation over time of the materials currently used for the storage, transport, distribution and use of natural gas. The compatibility of these materials with natural gas including of hydrogen is dependent on the proportion of hydrogen added to the gas and is assessed with regard to several criteria: Permeation of hydrogen through metallic materials; loss of integrity of these materials and adaptation of follow-up actions in service, surveillance and maintenance of equipment. This paper is devoted to the effect of hydrogen embrittlement (HE) by adding hydrogen into natural gas network on design, maintenance, supervision and maximum allowable operating pressure (MAOP) for smooth and damaged pipes.

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