scholarly journals Resistance to brittle fracture and availability of austenitic steels

Author(s):  
Boris Ermakov ◽  
S Vologzhanina ◽  
Igor Bobrovskij ◽  
Nikolai Bobrovskij ◽  
Yaroslav Erisov
Alloy Digest ◽  
1980 ◽  
Vol 29 (11) ◽  

Abstract The 21/4% Nickel Steel possesses a combination of moderate strength and superior resistance to brittle fracture at subzero temperatures. It is one of the most economical materials for the construction of equipment to operate at temperatures as low as -90 F. It is intended primarily for welded pressure vessels. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-378. Producer or source: Alloy steel mills and foundries.


2018 ◽  
Author(s):  
S. V. Gladkovsky ◽  
I. S. Kamantsev ◽  
S. V. Kuteneva ◽  
D. A. Dvoynikov ◽  
A. V. Kuznetsov

Author(s):  
V.S. Chmeliova ◽  
H.I. Perchun

Purpose. Questions about ways to increase the structural strength of oil country tubular goods are considered. Alloying and heat treatment of medium-alloy steels should ensure: pro-carbonization to the structure of martensite and lower bainite with a minimum carbon content (C ≤ 0.3 %), high resistance to brittle fracture and hydrogen embrittlement, the formation of uniformly distributed finely dispersed carbides and sulphides of a round shape to reduce diffusion mobile hydrogen is absorbed by steel. Propose modes of thermal treatment of casing pipes that provide the required level of mechanical and operational properties. Methodology. We used standard techniques for determining the mechanical properties in tension, dynamic bending tests and fracture studies. Results. The modes of heat treatment of casing pipes of strength category E, L are proposed, which provide the required level of mechanical and operational properties and an increase in structural strength. Originality. A systematic analysis of the influence of various factors on the structural strength of oil country tubular goods operating in an aggressive environment has been carried out. The highest degree of correlation between the value of the impact toughness and the tough component in the fracture is shown. Cooling of pipes with a nozzle sprayer of the design of the Department of Heat Treatment of Metals of NMetAU, which provides high resistance to brittle fracture by increasing the proportion of the viscous component and changing the microrelief of the cup fracture. Practical value. The proposed technology of heat treatment of oil pipes, working in an aggressive environment, provides the required level of mechanical properties and resistance to hydrogen sulfide cracking. Keywords: structural strength; oil country tubular goods; alloying; heat treatment; strength categories;temperature and deformation parameters; hydrogen sulfide cracking; brittle fracture resistance


Author(s):  
A.P. Korchagin ◽  
◽  
K.A. Kuznetsov ◽  
A.M. Kuznetsov ◽  
S.I. Kirillov ◽  
...  

The problem of assessing steels durability, their resistance to brittle fracture in the structures used in various branches of industry, remains relevant at the development of the new equipment and control of the old equipment. Standard strength calculations do not give a complete picture of the ability of steels due to their physical and mechanical properties to resist the formation and further development of defects and cracks under the action of actual stresses. The correct choice of a structural material for technical devices operating at low temperatures, knowledge of its characteristics of resistance to brittle fracture, understanding of brittle fracture mechanism at low temperatures and research in this area are of great importance. Since 1980s, JSC IrkutskNIIkhimmash systematically conducts the research works related to impact strength characteristics. These works are carried out in connection with the need for assessing the resistance to brittle fracture of metal of the equipment for storing oil products, vessels and pipelines, drill pipes and tubing, etc. As a result of many years of research, the authors accumulated significant experimental material in the form of temperature dependences of impact strength - both for the material of various types of blanks (sheets, pipes, forgings) in the state of delivery, and for the metal of technical devices elements after their operation of various duration. The main objective of the article is to assist specialists in establishing the correct choice of steel for the new or old structures in terms of their resistance to brittle fracture without conducting special studies. Specialists can select the closest steel analogue (on chemical composition, mechanical properties, and the type of product without making cuts from the structure or blanks for additional research), and set the numerical value of the impact strength, critical temperature of brittleness and the stress intensity factor for any temperature in the range from –40 to 20° С in order to use them in further calculations.


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