scholarly journals Prediction of Microstructure Constituents’ Hardness after the Isothermal Decomposition of Austenite

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 180
Author(s):  
Sunčana Smokvina Hanza ◽  
Božo Smoljan ◽  
Lovro Štic ◽  
Krunoslav Hajdek
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Carbon Content ◽  
Deep Understanding ◽  
Low Alloy Steels ◽  
Isothermal Decomposition ◽  
Technical Requirements ◽  
Proposed Model ◽  
Alloy Steels ◽  
Prediction Of Mechanical Properties

An increase in technical requirements related to the prediction of mechanical properties of steel engineering components requires a deep understanding of relations which exist between microstructure, chemical composition and mechanical properties. This paper is dedicated to the research of the relation between steel hardness with the microstructure, chemical composition and temperature of isothermal decomposition of austenite. When setting the equations for predicting the hardness of microstructure constituents, it was assumed that: (1) The pearlite hardness depends on the carbon content in a steel and on the undercooling below the critical temperature, (2) the martensite hardness depends primarily on its carbon content, (3) the hardness of bainite can be between that of untempered martensite and pearlite in the same steel. The equations for estimation of microstructure constituents’ hardness after the isothermal decomposition of austenite have been proposed. By the comparison of predicted hardness using a mathematical model with experimental results, it can be concluded that hardness of considered low-alloy steels could be successfully predicted by the proposed model.

scholarly journals Mechanical properties of low-alloy-steels with bainitic microstructures and varying carbon content

2016 ◽  
Vol 119 ◽  
pp. 012005
Author(s):  
A Weber ◽  
J Klarner ◽  
T Vogl ◽  
R Schöngrundner ◽  
G Sam ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Content ◽  
Low Alloy Steels ◽  
Alloy Steels

STUDY OF HIGH-STRENGTH LOW-ALLOY STEEL WITH SUPER-EQUILIBRIUM NITROGEN CONTENT

2020 ◽  
pp. 3-13
Author(s):  
S.A. Krylov ◽  
◽  
A.A. Makarov ◽  
M.A. Druzhnov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Nitrogen Content ◽  
Mechanical Characteristics ◽  
High Strength ◽  
Low Alloy Steels ◽  
Low Alloy Steel ◽  
Joint Work ◽  
Alloy Steels ◽  
High Level

In continuation of joint work of FSUE «VIAM» and IMET RAN named after Baikov, in the field of obtaining low-alloy steels with increased mechanical properties with a super-equilibrium nitrogen content, the mechanical properties, structure, and chemical composition of the obtained steel were studied. It is shown that steel 10KH3A with a super-equilibrium nitrogen content (up to 0,2) electroslag remelting under pressure DESHP-0,1 (FSUE «VIAM») provides a high level of properties (ultimate strength 1670 MPa) while maintaining high mechanical characteristics (elongation 10%, constriction 50%).

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

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).

MECHANICAL PROPERTIES OF SINTER/FORGED LOW-ALLOY STEELS

1970 ◽  
Vol 13 (26) ◽  
pp. 165-194 ◽  
Author(s):  
R. T. CUNDILL ◽  
E. MARSH ◽  
K. A. RIDAL
Keyword(s):  
Mechanical Properties ◽  
Low Alloy Steels ◽  
Alloy Steels

Hydrogen Compatibility and Suitability of (Ni)-Cr-Mo High-Strength Low-Alloy Seamless Line Pipe Steels for Pressure Vessels for Hydrogen Storage

2018 ◽  
Author(s):  
Akihide Nagao ◽  
Nobuyuki Ishikawa ◽  
Toshio Takano
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Strength ◽  
Pressure Vessels ◽  
Hydrogen Gas ◽  
Low Alloy Steels ◽  
Pipe Steels ◽  
Line Pipe ◽  
Alloy Steels ◽  
Pressure Hydrogen

Cr-Mo and Ni-Cr-Mo high-strength low-alloy steels are candidate materials for the storage of high-pressure hydrogen gas. Forging materials of these steels have been used for such an environment, while there has been a strong demand for a higher performance material with high resistance to hydrogen embrittlement at lower cost. Thus, mechanical properties of Cr-Mo and Ni-Cr-Mo steels made of quenched and tempered seamless pipes in high-pressure hydrogen gas up to 105 MPa were examined in this study. The mechanical properties were deteriorated in the presence of hydrogen that appeared in reduction in local elongation, decrease in fracture toughness and accelerated fatigue-crack growth rate, although the presence of hydrogen did not affect yield and ultimate tensile strengths and made little difference to the fatigue endurance limit. It is proposed that pressure vessels for the storage of gaseous hydrogen made of these seamless line pipe steels can be designed.

Fast Fracture Evaluation of Steam Generator Channel Heads Considering High Carbon Macro-Segregation

2020 ◽  
Author(s):  
Kaikai Shi ◽  
Yixiong Zhang ◽  
Yu Yang ◽  
Bin Zheng ◽  
Hai Xie ◽  
...  
Keyword(s):  
Stress Intensity Factor ◽  
Transition Temperature ◽  
Stress Intensity ◽  
Carbon Content ◽  
Steam Generator ◽  
Low Alloy Steels ◽  
High Carbon ◽  
Fracture Failure ◽  
Alloy Steels ◽  
Fast Fracture

Abstract The Fracture evaluation is important in the structural integrity analysis of nuclear equipment which is subjected to the effects of neutron irradiation. The increment of ductile and brittle transition temperature is mainly due to the neutron irradiation, thermal ageing and strain ageing. In addition to above these factors, the high carbon macro-segregation of low-alloy steels also increases the risk of fast fracture failure as the carbon positive macro-segregation will lead to the increasing transition temperature of low-alloy steels. In this work, a relationship between the carbon content and the increment of transition temperature is developed and is used to the fast fracture failure analysis of the highest carbon content region in steam generator channel head. Results show that ratio between the calculated stress intensity factor considering safety coefficient suggested by ASME design code and the critical stress intensity factor is less than one, which indicates a safe design for the highest carbon content region in steam generator channel head.

Formation of Ultrafine Grained Ferrite by Warm Deformation of Tempered Lath Martensite in Low Alloy Steels

2007 ◽  
Vol 558-559 ◽  
pp. 557-562 ◽  
Author(s):  
Behrang Poorganji ◽  
Takuto Yamaguchi ◽  
Tadashi Maki ◽  
G. Miyamoto ◽  
Tadashi Furuhara
Keyword(s):  
Grain Size ◽  
Carbon Content ◽  
Volume Fraction ◽  
Boundary Migration ◽  
Lath Martensite ◽  
Second Phase ◽  
Low Alloy Steels ◽  
Warm Deformation ◽  
Alloy Steels ◽  
Block Width

Microstructure change during warm deformation of tempered lath martensite in Fe-2mass%Mn-C alloys with different carbon contents in the range between 0.1 and 0.8mass%C was investigated. Specimens of the alloys after being quenched and tempered at 923K for 0.3ks were compressed by 50% with a strain rate varying from 10-3 to 10-4s-1 at 923K. EBSD analysis of the deformed microstructures has revealed that fine equiaxed ferrite (α) grains surrounded by high-angle boundaries are formed by dynamic recrystallization (DRX). As carbon content increases, the DRX α grain size decreases. This could be attributed to the change in volume fraction of the cementite (θ) phase as boundary dragging particles. The sub-micron θ particles can suppress the coarsening of the DRX α grains by exerting a pinning effect on grain boundary migration. Furthermore, the fraction of recrystallized region increases by increasing carbon content, presumably due to a decrease in the martensite block width as an initial α grain size and a larger volume fraction of hard second phase (θ) particles. Both of these should increase inhomogeneous plastic deformation which promotes the recrystallization. It seems that continuous DRX is responsible for the formation of ultrafine α grains in the tempered lath martensite.

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