Mechanical Properties of High-Manganese Austenitic TWIP-Type Steel

2014 ◽  
Vol 783-786 ◽  
pp. 27-32 ◽  
Author(s):  
Leszek Adam Dobrzański ◽  
Wojciech Borek ◽  
Janusz Mazurkiewicz
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
High Strength ◽  
Deformation Energy ◽  
Mechanical Twinning ◽  
Austenitic Steels ◽  
Manganese Steel ◽  
Cold Plastic Deformation ◽  
High Plasticity ◽  
High Manganese

Taking into consideration increased quantity of accessories used in modern cars, decreasing car’s weight can be achieved solely by optimization of sections of sheets used for bearing and reinforcing elements as well as for body panelling parts of a car. Application of sheets with lower thickness requires using sheets with higher mechanical properties, however keeping adequate formability. The goal of structural elements such as frontal frame side members, bumpers and the others is to take over the energy of an impact. Therefore, steels that are used for these parts should be characterized by high value of UTS and UEl, proving the ability of energy absorption. Among the wide variety of recently developed steels, high-manganese austenitic steels with low stacking faulty energy are particularly promising, especially when mechanical twinning occurs. Beneficial combination of high strength and ductile properties of these steels depends on structural processes taking place during cold plastic deformation, which are a derivative of SFE of austenite, dependent, in turn on the chemical composition of steel and deformation temperature. High-manganese austenitic steels in effect of application of proper heat treatment or thermo-mechanical treatment can be characterized by different structure assuring the advantageous connection of strength and plasticity properties. Proper determinant of these properties can be plastic deformation energy supply determined by integral over surface of cold plastic deformation curve. Obtaining of high strength properties with retaining the high plasticity has significant influence for the development of high-manganese steel groups and their significance for the development of materials engineering.

Microstructure and Mechanical Properties of High Manganese TWIP Steel after Thermo-Forming Processes

2015 ◽  
Vol 226 ◽  
pp. 99-102
Author(s):  
Magdalena Jabłońska ◽  
Dariusz Kuc ◽  
Karina Horzelska ◽  
Anna Śmiglewicz
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Twip Steel ◽  
High Strength ◽  
Tensile Tests ◽  
Mechanical Twinning ◽  
High Manganese ◽  
Final Thickness ◽  
Hardening Mechanism ◽  
Finish Rolling

In recent years, the leading scientific centres focus their research on improvement of mechanical properties of steels used for car manufacturing. These steels belong to a so-called 2nd generation of steels showing above-the-average plasticity while maintaining high strength. Thanks to these properties, they may be used successfully in automotive, armaments or railway industries for elements absorbing energy of a collision and ensuring high rigidity of a structure owing to their resistance to breaking. These steels are called TWIP (Twinning Induced Plasticity) steels based on their hardening mechanism. In this paper, results of studies on the influence of parameters of thermo-plastic deformation on selected properties and structure of an X45MnAl20-3V austenitic steel showing the TWIP effect are presented. Moreover, an analysis of influence of the deformation on the structure of the studied steel in tensile tests has been carried out. The studied steel was manufactured by classic casting to a concast mould, obtaining ingots with dimensions of 100×100 mm, then subjected to rolling in 4 roll passes to a final thickness of 12 mm and 3 mm. The finish-rolling temperature was 950°C and the sheets were cooled in 2 media, i.e. in air and in water. It was confirmed that the studied steel belongs to the TWIP group of steels, with mechanical twinning being the prevailing process of hardening during deformation.

The Influence of Thermomechanical Controlled Processing on Bainite Formation in Low Carbon High Strength Steel

2014 ◽  
Vol 783-786 ◽  
pp. 21-26
Author(s):  
Xiao Jun Liang ◽  
Ming Jian Hua ◽  
Anthony J. DeArdo
Keyword(s):  
Mechanical Properties ◽  
High Strength Steel ◽  
High Strength ◽  
Manganese Steel ◽  
Low Carbon ◽  
High Manganese ◽  
Bainite Transformation ◽  
High Manganese Steel ◽  
Cooling Rates ◽  
Controlled Processing

Thermomechanical controlled processing is a very important way to control the microstructure and mechanical properties in low carbon, high strength steel. This is especially true in the case of bainite formation, where the complexity of the austenite-bainite transformation makes the control of the processing important. In this study, a low carbon, high manganese steel containing niobium was investigated to better understand the roles of austenite conditioning and cooling rates on the bainitic phase transformation. Specimens were compared with and without deformation, and followed by seven different cooling rates ranging between 0.5°C/s and 40°C/s. The CCT curves showed that the transformation behaviors and temperatures are very different. The different bainitic microstructures which varied with austenite deformation and cooling rates will be discussed.

scholarly journals Light non-magnetic steels based on Fe – 25 Mn – 5 Ni – Al – C system

2020 ◽  
Vol 63 (1) ◽  
pp. 47-56 ◽  
Author(s):  
L. M. Kaputkina ◽  
A. G. Svyazhin ◽  
I. V. Smarygina ◽  
V. E. Kindop
Keyword(s):  
Phase Structure ◽  
High Strength ◽  
Mechanical Tests ◽  
Austenitic Steels ◽  
High Plasticity ◽  
Cast State ◽  
High Manganese ◽  
Two Phase ◽  
Specific Strength ◽  
Al Content

1.7 %) contents on phase transformations, structure formation processes and mechanical properties of Fe – 25Mn – 5Ni – Al – C steels was studied theoretically and experimentally. The authors have estimated intervals of optimal crystallization regimes and subsequent deformation-thermal effects for obtaining austenitic steels with high specific strength. Measurements of hardness on the section of samples and mechanical tests in a wide interval of temperatures of cold, warm and hot deformation were performed as well as the assessment of phase structure of steels (alloys) on the basis of Fe – 25Mn – 5Ni– – Al – C. In a cast state alloy with 5 % of Al was non-magnetic, i.e. it had austenitic structure; alloys with 10 – 15 % of Al were magnetic with two-phase structure (γ + α). Aluminum considerably increases deformation resistance. At the same time values σ1 and σmax grow, i.e. also deformation hardening grows and softening processes are slowed down. With growth of deformation rate, influence of Al becomes stronger. Austenitic high-manganese alloys with 5 % of Al both with low and with high content of carbon have rather high plasticity and durability, and differ in high stability of austenite. Alloying with nickel increases plasticity. Alloys with Al less than 10 % are rather plastic also in a cast state. High-manganese (from 25 % of Mn) alloys with Al content to 5 – 7 % can be considered as high-strength cold-resistant and heat-resistant with thermally and mechanically stable austenite up to carbon content ~1.5 %.

scholarly journals Complex Structural Effects in Deformed High-Manganese Steel

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6935
Author(s):  
Joanna Kowalska ◽  
Janusz Ryś ◽  
Grzegorz Cempura
Keyword(s):  
Mechanical Properties ◽  
Phase Transformations ◽  
Mechanical Twinning ◽  
Carbon Steels ◽  
Deformation Mechanisms ◽  
Manganese Steel ◽  
Dislocation Slip ◽  
Chemical Compositions ◽  
High Manganese ◽  
Deformation Degree

The research presented in this paper is part of a larger project concerning deformation behavior, microstructure and mechanical properties of high-manganese steels with different chemical compositions and processed under various conditions. The current investigation deals with the development of microstructure and crystallographic texture of Fe-21.2Mn-2.73Al-2.99Si steel deformed in tension until fracture at ambient temperature. The deformation process of the examined steel turned out to be complex and included not only dislocation slip and twinning but also strain induced phase transformations (g ® e) and (g ® a′). The formation of e-martensite with hexagonal structure was observed within the microstructure of the steel starting from the range of lower strains. With increasing deformation degree, the a′-martensite showing a cubic structure gradually began to form. Attempts have been made to explain the circumstances or conditions for the occurrence of the deformation mechanisms mentioned above and their impact on the mechanical properties. The obtained results indicate that the strength and plastic properties of the steel substantially exceed those of plain carbon steels. Since both, mechanical twinning and the strain-induced phase transformations took place during deformation, it seems that both types of deformation mechanisms contributed to an increase in the mechanical properties of the examined manganese steel.

Studies on the Corrosion Properties of High-Mn Austenitic Steels

2015 ◽  
Vol 227 ◽  
pp. 75-78 ◽  
Author(s):  
Magdalena Jabłońska ◽  
Rafał Michalik
Keyword(s):  
Materials Science ◽  
High Strength ◽  
Corrosion Current ◽  
Austenitic Steels ◽  
Manganese Steel ◽  
Nacl Solution ◽  
High Manganese ◽  
Corrosion Properties ◽  
University Of Technology ◽  
New Type

Institute of Materials Science at Silesian University of Technology since 6 years conducts researches to learn about the new dedicated for automotive, railway and military industries. Some of these materials belong to the group of AHS steels, characterized by the twinning induced plasticity (TWIP) effect. It is a new type of steel possessing both a high strength and a great plastic elongation, and an ideal uniform work hardening behaviour. It is therefore a good candidate for deep drawing applications in the automobile and railway industries. In the paper the of the three grades of high-manganese steels of was studied in 3.5% NaCl solution and in an “acid rain” solution with pH=3.5 environments using polarization experiments. The results of corrosion tests and analysis of show that a higher polarisation resistance and lower values of corrosion current density are observed for all studied steels in 3.5% NaCl solution. Spontaneous passivation ability has been shown only for one grade of high-manganese steel in 3.5% NaCl.

ALLEGHENY LUDLUM TYPE 205

Alloy Digest ◽  
1997 ◽  
Vol 46 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Magnetic Permeability ◽  
Cold Working ◽  
High Strength ◽  
Heat Treating ◽  
Austenitic Steels

Abstract Allegheny Stainless Type 205 is a chromium-manganese nitrogen austenitic high strength stainless steel that maintains its low magnetic permeability even after large amounts of cold working. Annealed Type 205 has higher mechanical properties than any of the conventional austenitic steels-and for any given strength level, the ductility of Type 205 is comparable to that of Type 301. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SS-640. Producer or source: Allegheny Ludlum Corporation. Originally published March 1996, revised October 1997.

scholarly journals Formation of microstructure and properties of Cu-3Ti alloy in thermal and thermomechanical processes

2017 ◽  
Vol 62 (1) ◽  
pp. 223-230 ◽  
Author(s):  
A. Szkliniarz
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Plastic Deformation ◽  
Cold Working ◽  
Cold Deformation ◽  
Solution Treatment ◽  
Cold Plastic Deformation ◽  
Working Solution ◽  
Thermomechanical Processes ◽  
Selection Of

Abstract This paper presents the possibilities of forming the microstructure as well as mechanical properties and electrical conductivity of Cu-3Ti alloy (wt.%) in thermal and thermomechanical processes that are a combination of homogenising treatment, hot and cold working, solution treatment and ageing. Phase composition of the alloy following various stages of processing it into the specified semi-finished product was being determined too. It was demonstrated that the application of cold plastic deformation between solution treatment and ageing could significantly enhance the effect of hardening of the Cu-3Ti alloy without deteriorating its electrical conductivity. It was found that for the investigated alloy the selection of appropriate conditions for homogenising treatment, hot and cold deformation as well as solution treatment and ageing enables to obtain the properties comparable to those of beryllium bronzes.

Microstructure Evolution and Deformation Mechanisms of Harmonic Structure Designed Materials

2016 ◽  
Vol 879 ◽  
pp. 145-150
Author(s):  
Kei Ameyama ◽  
Sanjay Kumar Vajpai ◽  
Mie Ota
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Powder Metallurgy ◽  
Early Stage ◽  
High Strength ◽  
Plastic Instability ◽  
Structure Design ◽  
Harmonic Structure ◽  
Homogeneous Microstructure ◽  
Macro Scale

This paper presents the novel microstructure design, called Harmonic Structure, which gives structural metallic materials outstanding mechanical properties through an innovative powder metallurgy process. Homogeneous and ultra-fine grain (UFG) structure enables the materials high strength. However, such a “Homo-“ and “UFG” microstructure does not, usually, satisfy the need to be both strong and ductile, due to the plastic instability in the early stage of the deformation. As opposed to such a “Homo-and UFG“ microstructure, “Harmonic Structure” has a heterogeneous microstructure consisting of bimodal grain size together with a controlled and specific topological distribution of fine and coarse grains. In other words, the harmonic structure is heterogeneous on micro-but homogeneous on macro-scales. In the present work, the harmonic structure design has been applied to pure metals and alloys via a powder metallurgy route consisting of controlled severe plastic deformation of the corresponding powders by mechanical milling or high pressure gas milling, and subsequent consolidation by SPS. At a macro-scale, the harmonic structure materials exhibited superior combination of strength and ductility as compared to their homogeneous microstructure counterparts. This behavior was essentially related to the ability of the harmonic structure to promote the uniform distribution of strain during plastic deformation, leading to improved mechanical properties by avoiding or delaying localized plastic instability.

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