Metastable Austenite Steel Structure After Thermomechanical Processing in Different Modes

2021 ◽  
Author(s):  
G. V. Shlyakhova ◽  
D. V. Orlova ◽  
V. I. Danilov ◽  
L. V. Danilova
Keyword(s):  
Thermomechanical Processing ◽  
Steel Structure ◽  
Metastable Austenite ◽  
Austenite Steel

Rolling Contact Fatigue of Hot-Forged Steels out of Prealloyed Powders and Powder Blend

2007 ◽  
Vol 534-536 ◽  
pp. 709-712
Author(s):  
Vladimir Dorofeyev ◽  
Anna Sviridova
Keyword(s):  
Thermomechanical Treatment ◽  
Rolling Contact Fatigue ◽  
Hot Forging ◽  
Contact Fatigue ◽  
Steel Structure ◽  
Rolling Contact ◽  
Metastable Austenite ◽  
Practical Utilization ◽  
Metallic Inclusions ◽  
Optimal Values

Powder forging is used for heavy-loaded parts (rings of rolling-contact bearings, gears etc.) production. Rolling contact fatigue is material property values of which characterize possibility of practical utilization of such parts. Rolling contact fatigue of some steels obtained out of prealloyed powders Astaloy CrM, Atomet 4601, Atomet 4901 and powder blends iron-carbon-nickel by hot forging is studied in the present paper. Effect of various kinds of heat and thermomechanical treatment on rolling contact fatigue is determined. Thermomechanical treatment provides optimal values of rolling contact fatigue. In this case steel structure contains up to 40% of retained metastable austenite which is transformed to martensite on trials. Thus typically crack is generated on residual pores and non-metallic inclusions instead of martensite zones in wrought steels.

Integral Computer Model for Simulating Microstructure Evolution during Thermomechanical Processing and Heat Treatment of Steels and Predicting their Final Mechanical Properties

2021 ◽  
Vol 1016 ◽  
pp. 1532-1537
Author(s):  
Alexander Alexandrovich Vasilyev ◽  
Dmitry Sokolov ◽  
Semen Sokolov ◽  
N.G. Kolbasnikov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Computer Model ◽  
Thermomechanical Processing ◽  
Quantitative Description ◽  
Experimental Studies ◽  
Steel Structure ◽  
Chemical Compositions ◽  
Steel Microstructure ◽  
Physically Based

An integral computer model/program AusEvol Pro was developed to describe the evolution of steel microstructure during thermomechanical processing (hot rolling, forging), as well as subsequent heat treatment (normalization, tempering), and to evaluate the final mechanical properties (yield stress, tensile stress, elongation), hardness and impact toughness. The program implements a set of physically based models that allow quantitative description of all significant processes of steel structure formation with account of the effects of chemical composition both during thermomechanical processing and heat treatment. Calculations of the final mechanical properties are carried out using the developed models that take into account all physically meaningful contributions. The models created are verified both on the extensive database of our own experimental studies and on reliable data from literature for steels of various chemical compositions.

Effect of Electropulsing on the Fatigue Behavior and Change in the Austenite Steel Structure

2017 ◽  
Vol 906 ◽  
pp. 26-31 ◽  
Author(s):  
Sergey V. Konovalov ◽  
D.A. Kosinov ◽  
I.A. Komissarova ◽  
V.E. Gromov
Keyword(s):  
Fatigue Life ◽  
Dynamic Recrystallization ◽  
Dislocation Substructure ◽  
Fatigue Behavior ◽  
Steel Structure ◽  
Grain Structure ◽  
Local Dynamic ◽  
Initial State ◽  
Electron Microscopic ◽  
Austenite Steel

The tests were carried out to identify the influence of electropulse treatment on austenite steel ((mass %) 0.44С, 16.50Mn, 0.26Cr, 0.08Ni, 0.34Si, 2.74Al, 0.002S, 0.017P, Fe – balance). The fa-tigue life is reported to increase by 1.8 times. Electron microscopic research into the dislocation structure of the steel was conducted under diverse fatigue conditions with the purpose to give rea-sons for the identified effect. The dislocation chaos substructure, reticular and fragmented dislocation substructures were found in the steel in the initial state. Fatiguing leads to the change in the dis-location substructure parameters. The subsequent electropulse treatment furthers transformation of the grain structure since grains arise and grow due to evolving local dynamic recrystallization and partial transformation of the dislocation substructure and occurrence of a great number of microtwins. The increase in the fatigue life is associated with the mentioned above transformations resulting from electropulse treatment of the steel structural state.

scholarly journals Influence of Strain Rate on TRIP Effect in SUS301L Metastable Austenite Steel

2011 ◽  
Vol 97 (8) ◽  
pp. 450-456 ◽  
Author(s):  
Yoshinori Takagi ◽  
Rintaro Ueji ◽  
Takashi Mizuguchi ◽  
Noriyuki Tsuchida
Keyword(s):  
Strain Rate ◽  
Trip Effect ◽  
Metastable Austenite ◽  
Austenite Steel

Variation of elastic characteristics of metastable austenite steel under cycling straining

2017 ◽  
Vol 62 (4) ◽  
pp. 537-541 ◽  
Author(s):  
A. V. Gonchar ◽  
V. V. Mishakin ◽  
V. A. Klyushnikov ◽  
K. V. Kurashkin
Keyword(s):  
Metastable Austenite ◽  
Austenite Steel ◽  
Elastic Characteristics

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

High-resolution x-ray imaging of small copper-rich precipitates in steels

1988 ◽  
Vol 46 ◽  
pp. 528-529
Author(s):  
J. R. Michael ◽  
K. A. Taylor
Keyword(s):  
Electron Microscopy ◽  
Thermomechanical Processing ◽  
Atom Probe ◽  
Ferrite Matrix ◽  
Scanning Transmission Electron Microscope ◽  
Probe Field ◽  
X Ray ◽  
Subsequent Transformation ◽  
Transmission Electron ◽  
Scanning Transmission

Although copper is considered an incidental or trace element in many commercial steels, some grades contain up to 1-2 wt.% Cu for precipitation strengthening. Previous electron microscopy and atom-probe/field-ion microscopy (AP/FIM) studies indicate that the precipitation of copper from ferrite proceeds with the formation of Cu-rich bcc zones and the subsequent transformation of these zones to fcc copper particles. However, the similarity between the atomic scattering amplitudes for iron and copper and the small misfit between between Cu-rich particles and the ferrite matrix preclude the detection of small (<5 nm) Cu-rich particles by conventional transmission electron microscopy; such particles have been imaged directly only by FIM. Here results are presented whereby the Cu Kα x-ray signal was used in a dedicated scanning transmission electron microscope (STEM) to image small Cu-rich particles in a steel. The capability to detect these small particles is expected to be helpful in understanding the behavior of copper in steels during thermomechanical processing and heat treatment.

Regeneration of a historic city block: the example of the relocation of the historic Atelier building to the cloister area of the Congregation of the Resurrection in Krakow

2019 ◽  
Vol 63 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Bogusław Podhalański ◽  
Anna Połtowicz
Keyword(s):  
Twentieth Century ◽  
Cultural Heritage ◽  
Steel Structure ◽  
City Block ◽  
Raising Awareness ◽  
Straight Line ◽  
Heritage Buildings ◽  
Heritage Building ◽  
Historic City ◽  
The City

Abstract The article discusses a project that features the relocation of the historic Atelier building, built by Krakow-based architect Wandalin Beringer (1839–1923) who was active in the early twentieth century, and the regeneration of a plot belonging to the Congregation of the Resurrection since 1885, which is located at 12 Łobzowska Street in Krakow. The method includes cutting the entire structure off at the foundation and then after reinforcing it with a steel structure transporting it in its entirety to the new location. The project included two possible variants of moving the building in a straight line, either by 21 or 59 metres and evaluates two projects of further regeneration, the adaptive reuse of the building as an exhibition and religious space as well as a proposal for the remodelling of the nearby plot that belongs to the Congregation into a space for meditation and as a recreational park. The aim of these measures is to prevent the demolition of this building, now over a century old, as a result of which a forgotten element of the cultural heritage of the city will be saved. This project was based on the results of analyses of the cultural and historical conditions of Krakow. The block of buildings in which the Atelier in question is located is a very attractive location, near to the very centre of Krakow, adjacent to residential, service and educational buildings. It is directly adjacent to the Monastery Complex of the Congregation of the Resurrection, listed as a heritage building under conservation protection (municipal registry of heritage buildings). In the second half of the twentieth century, the building was used as a workroom by artists such as Xawery Dunikowski and later by the sculptress Teodora Stasiak. The case of the Atelier may provide an inspiration for discussion as well as raising awareness among citizens and city authorities to avoid future situations in which cultural heritage may become forgotten or demolished.

Structural features and strength behavior of TRIP/TWIP steels

2020 ◽  
pp. 5-18
Author(s):  
D. V. Prosvirnin ◽  
◽  
M. S. Larionov ◽  
S. V. Pivovarchik ◽  
A. G. Kolmakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermomechanical Processing ◽  
Maximum Load ◽  
Structural Features ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Structural And Functional Properties ◽  
Twip Steels ◽  
The Creation

A review of the literature data on the structural features of TRIP / TWIP steels, their relationship with mechanical properties and the relationship of strength parameters under static and cyclic loading was carried out. It is shown that the level of mechanical properties of such steels is determined by the chemical composition and processing technology (thermal and thermomechanical processing, hot and cold pressure treatment), aimed at achieving a favorable phase composition. At the atomic level, the most important factor is stacking fault energy, the level of which will be decisive in the formation of austenite twins and / or the formation of strain martensite. By selecting the chemical composition, it is possible to set the stacking fault energy corresponding to the necessary mechanical characteristics. In the case of cyclic loads, an important role is played by the strain rate and the maximum load during testing. So at high loading rates and a load approaching the yield strength under tension, the intensity of the twinning processes and the formation of martensite increases. It is shown that one of the relevant ways to further increase of the structural and functional properties of TRIP and TWIP steels is the creation of composite materials on their basis. At present, surface modification and coating, especially by ion-vacuum methods, can be considered the most promising direction for the creation of such composites.

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