Effects of Temperature and Dissolved Oxygen Contents on Fatigue Lives of Carbon and Low Alloy Steels in LWR Water Environments

Author(s):  
G Nakao ◽  
M Higuchi ◽  
H Kanasaki ◽  
K Iida ◽  
Y Asada
Author(s):  
Makoto Higuchi ◽  
Katsumi Sakaguchi ◽  
Akihiko Hirano ◽  
Yuichiro Nomura

Low cycle fatigue life of carbon and low alloy steels reduces remarkably as functions of strain rate, temperature, dissolved oxygen and sulfur in steel in high temperature water simulating LWR coolant. A model for predicting such fatigue life reduction was first proposed in the early 1980s and since then has been revised several times. The existing model established in 2000 is used for the MITI Guideline [6] and the TENPES Guideline [7] which stipulate procedures for evaluating environmental fatigue damage at LWR plants in Japan. This paper presents the most recent environmental fatigue evaluation model derived based on additional fatigue data provided by the EFT Project over the past five years. This model differs not significantly with previous version but does provide more accurate equations for the susceptibility of fatigue life to sulfur in steel, strain rate, temperature and dissolved oxygen. Test data on environmental fatigue of nickel base alloys are available only to a limited extent and there is yet no model for predicting fatigue life reduction in such an environment. The EFT Project has made available considerable environmental fatigue test data and developed a new model for calculating Fen of nickel base alloys. The contribution of environment to fatigue of nickel base alloy is much less compared to that in austenitic stainless steel.


1985 ◽  
Vol 107 (4) ◽  
pp. 430-435 ◽  
Author(s):  
J. Kuniya ◽  
I. Masaoka ◽  
R. Sasaki ◽  
H. Itoh ◽  
T. Okazaki

Studies have been done on stress corrosion cracking (SCC) susceptibility of low alloy steels in water containing dissolved oxygen. The fundamental factors which affect the SCC susceptibility were clarified, and the integrity of the reactor pressure vessel (RPV), in which these steels are used, was assessed from the standpoint of SCC initiation. The effects of applied stress, strain rate, dissolved oxygen concentration, and test temperatures, on the SCC susceptibility was examined utilizing uniaxial constant load tensile tests (UCL), and slow strain rate tests (SSRT).


Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).


2020 ◽  
Vol 2020 (10) ◽  
pp. 8-21
Author(s):  
A. G. Kolmakov ◽  
◽  
I. O. Bannykh ◽  
V. I. Antipov ◽  
L. V. Vinogradov ◽  
...  

he basic ideas about the process of introducing cores into protective barriers and the most common core patterns and their location in conventional and sub-caliber small arms bullets are discussed. The materials used for manufacture of cores are analyzed. It is concluded that for mass bullets of increased armor penetration the most rational choice can be considered the use of high-carbon low-alloy steels of a new generation with a natural composite structure and hardness of up to 70 HRC. For specialized armor-piercing bullets, cores made from promising economically-alloyed high-speed steels characterized by a high complex of «hardness—bending strength» are better alternative than ones made of hard alloys or tungsten alloys.


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