Effect of Al Content in Low Carbon High Manganese TWIP Steel

2016 ◽  
Vol 706 ◽  
pp. 16-22 ◽  
Author(s):  
Nisith Kumar Tewary ◽  
Swarup Kumar Ghosh ◽  
Subrata Chatterjee
Keyword(s):  
Tensile Strength ◽  
Twip Steel ◽  
Cold Deformation ◽  
Specific Weight ◽  
Total Elongation ◽  
Low Carbon ◽  
Duplex Microstructure ◽  
Al Content ◽  
Lower Elongation ◽  
Hot Rolled

Al addition in TWIP steel not only reduces the specific weight but also increases the stacking fault energy which strongly affects the deformation mechanisms. Hot rolled air cooled TWIP steel with low Al content (1.61 wt. %) reveals duplex microstructure comprising austenite with ferrite, whereas steel with higher content of Al (3.56 wt. %) reveals fully austenite microstructure. It is evident that nano-twins are formed within austenite grain after 50% cold deformation. TWIP steel with the duplex microstructure exhibits an excellent combination of strength and ductility. Hardness and tensile strength values of air cooled steel specimens increase with a concomitant lowering of total elongation with the application of cold deformation. However, steel with low Al content shows higher hardness and tensile strength along with lower elongation as compared to the TWIP steel having higher Al content.

Deformation behaviour of low carbon high Mn twinning-induced plasticity steel

2017 ◽  
Vol 233 (3) ◽  
pp. 763-771 ◽  
Author(s):  
NK Tewary ◽  
SK Ghosh ◽  
S Chatterjee
Keyword(s):  
Tensile Strength ◽  
Twip Steel ◽  
Deformation Behaviour ◽  
Cold Deformation ◽  
Solution Treatment ◽  
Low Carbon ◽  
High Manganese ◽  
Microstructural Investigation ◽  
Dislocation Interaction ◽  
Deformation Twins

The present study deals with the deformation behaviour of low carbon and high manganese twinning-induced plasticity (TWIP) steel (Fe–21Mn–3Si–3Al–0.06C, wt%) through microstructural investigation. Low carbon with high manganese along with the addition of aluminium in TWIP steel results in lowering of specific weight with higher strain hardening due to the formation of mechanical twins during deformation. The full austenite phase is obtained after solution treatment and deformation twins appear and austenite grains become flattened during application of 10% to 50% cold deformation. The annealing twins are relatively coarser compared to the newly formed deformation twins. With the increasing amount of cold deformation, deformation twins and dislocation density are increased. Deformation twinning can be considered to be the dominant deformation mechanism during the course of cold rolling applied in the present study. The cold deformation results in the evolution of dislocation substructure, stacking faults, deformation twins and twin–dislocation interaction, which may be correlated with the lower stacking fault energy (∼24 mJ/m2) of the investigated steel. Excellent combination of strength and ductility has been obtained in the present TWIP steel with a small rolling reduction of 10% and 30%. With the increasing amount of cold deformation, tensile strength notably increases and maximum tensile strength is obtained at 50% cold-deformed sample along with the diminutive sacrifice of the ductility.

scholarly journals Development of a Cr-Ni-V-N Medium Manganese Steel with Balanced Mechanical and Corrosion Properties

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 705 ◽  
Author(s):  
Tarek Allam ◽  
Xiaofei Guo ◽  
Simon Sevsek ◽  
Marta Lipińska-Chwałek ◽  
Atef Hamada ◽  
...  
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Twip Steel ◽  
Total Elongation ◽  
Manganese Steel ◽  
Ultrafine Grain ◽  
Corrosion Properties ◽  
Hot Rolled ◽  
20 Nm

A novel medium manganese (MMn) steel with additions of Cr (18%), Ni (5%), V (1%), and N (0.3%) was developed in order to provide an enhanced corrosion resistance along with a superior strength–ductility balance. The laboratory melted ingots were hot rolled, cold rolled, and finally annealed at 1000 °C for 3 min. The recrystallized single-phase austenitic microstructure consisted of ultrafine grains (~1.3 µm) with a substantial amount of Cr- and V-based precipitates in a bimodal particle size distribution (100–400 nm and <20 nm). The properties of the newly developed austenitic MMn steel X20CrNiMnVN18-5-10 were compared with the standard austenitic stainless steel X5CrNi18-8 and with the austenitic twinning-induced plasticity (TWIP) steel X60MnAl17-1. With a total elongation of 45%, the MMn steel showed an increase in yield strength by 300 MPa and in tensile strength by 150 MPa in comparison to both benchmark steels. No deformation twins were observed even after fracture for the MMn steel, which emphasizes the role of the grain size and precipitation-induced change in the austenite stability in controlling the deformation mechanism. The potentio-dynamic polarization measurements in 5% NaCl revealed a very low current density value of 7.2 × 10−4 mA/cm2 compared to that of TWIP steel X60MnAl17-1 of 8.2 × 10−3 mA/cm2, but it was relatively higher than that of stainless steel X5CrNi18-8 of 2.0 × 10−4 mA/cm2. This work demonstrates that the enhanced mechanical properties of the developed MMn steel are tailored by maintaining an ultrafine grain microstructure with a significant amount of nanoprecipitates, while the high corrosion resistance in 5% NaCl solution is attributed to the high Cr and N contents as well as to the ultrafine grain size.

Microstructure and Mechanical Properties of Nb Alloyed Steel Processed by Hot Equal Channel Angular Extrusion

2016 ◽  
Vol 879 ◽  
pp. 2528-2531
Author(s):  
Akira Yanagida ◽  
Ryo Aoki ◽  
Masataka Kobayashi
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Carbon Steel ◽  
Equal Channel Angular Extrusion ◽  
Low Carbon Steel ◽  
Total Elongation ◽  
Low Carbon ◽  
Angular Extrusion ◽  
Ferrite Grain Size

A Nb alloyed low carbon steel was processed by hot equal channel angular extrusion (ECAE) and following transformation. The workpieces were heated up to the 960°C in the furnace for 10 min within the container block. Before extrusion, the die was preheated to 400oC. The workpiece was cooled in the die after ECAE process. 1 pass and 2 pass via route C were conducted at a speed of 32mm/s, the inter-pass time is about 2 sec. The sample of average ferrite grain size of about 2μm, a tensile strength of 800MPa, a total elongation about 20% is produced after 2 pass ECAE processed and subsequent cooling.

Effect of Tempering Temperature on the Microstructure and Mechanical Properties of a 0.1C Steel with High Strength and Low Yield Ratio

2012 ◽  
Vol 535-537 ◽  
pp. 601-604
Author(s):  
Wen Hao Zhou ◽  
Hui Guo ◽  
Cheng Jia Shang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Major Change ◽  
Total Elongation ◽  
Yield Ratio ◽  
High Yield ◽  
Low Carbon ◽  
Tempering Temperature ◽  
Microstructure And Mechanical Properties

The influence of tempering temperature on the microstructure and mechanical properties of low carbon low alloy steel was investigated. The results show that tempering temperature has considerable influence on both yield strength and tensile strength. With the increase in tempering temperature, the yield strength increases first and then decreases after it reaches the highest point at 600°C with a strength of 843MPa, while the tensile strength decreases fastly from 550°C to 650°C and keeps stable after increasing drastically at 720°C. The yield ratio is about 0.60 except at 600°C and 650°C with a high yield ratio of 0.90, while the total elongation has little change. It is concluded that the major change of mechanical properties after tempering has a connection with the decomposition of M/A(martensite/austenite) islands, the recovery of dislocations and the precipitation of alloy elements.

Cold Deformation Effect on Microstructure and on the Hydrogen Permeability of Low Carbon Al-Killed Steels

2010 ◽  
Vol 659 ◽  
pp. 7-12 ◽  
Author(s):  
Fábián Enikő-Réka
Keyword(s):  
Cold Rolling ◽  
Hydrogen Permeability ◽  
Cold Deformation ◽  
Low Carbon Steel ◽  
Rolling Process ◽  
Low Carbon ◽  
Deformation Degree ◽  
Steel Sheets ◽  
Texture Modification ◽  
Hot Rolled

The cold rolling effect on the hydrogen permeability (TH value) and on the microstructure have been studied on samples prepared from Al-killed low carbon steel sheets after several cold rolling levels. The TH values of the hot rolled strips were very short, but due to the cold rolling increase exponentially. The fragmentation of large cementite phase has a significant influence on the evolution of texture during the cold rolling process. The cold deformation effects on the TH value were studied on four annealed enamelling grade steel sheets also. Depending on the carbides sizes and carbides position in ferrite grains after annealing the TH values increase or decrease after low deformation degrees, due to the steel texture modification and dislocation character. Dislocations act as major tripping site for hydrogen, if deformation degree is higher than 30%.

Low-Carbon Manganese TRIP Steels

2007 ◽  
Vol 539-543 ◽  
pp. 4327-4332 ◽  
Author(s):  
M.J. Merwin
Keyword(s):  
Manganese Content ◽  
High Strength ◽  
Total Elongation ◽  
Hot Strip Mill ◽  
Low Carbon ◽  
Trip Steels ◽  
Batch Annealing ◽  
Rolled Condition ◽  
Conventional Manner ◽  
Hot Rolled

The development of TRansformation Induced Plasicity (TRIP) steels has seen much activity in recent years, due to the promise of very high formability combined with high strength. The accepted method for production of as-hot-rolled TRIP steel employs multistage runout table cooling and coiling in the bainitic transformation temperature regime. As an alternative to confronting the production difficulties the accepted strategy presents, a program was begun to evaluate the potential of 0.1C-6.0Mn steels processed in a more conventional manner. Three laboratory heats were melted to consider the effect of manganese content on processing and properties. The steels were found to be fully hardenable with conventional hot-strip mill processing and subsequent batch annealing simulations produced significant retained austenite levels. The combination of the prior martensitic microstructure in the as-hot-rolled condition, and austenite created during annealing, resulted in remarkable combinations of strength and ductility. In the as-hot-rolled condition, tensile strengths exceeding 1400 MPa were observed, with total elongations of approximately 10 percent. Optimum properties were found when samples were annealed at approximately 650°C. While this treatment reduced the tensile strength to 800-1000 MPa, the total elongation increased to between 30 percent and 40 percent. UTS*TE products exceeding 30,000 MPa-% were observed, making these materials attractive for high strength, high ductility applications.

Ultrafine-Grained Structure and Mechanical Properties of a High-Mn Twinning Induced Plasticity Steel

2016 ◽  
Vol 838-839 ◽  
pp. 392-397 ◽  
Author(s):  
Pavel Kusakin ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev ◽  
Dmitri Molodov
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Cold Rolling ◽  
Twip Steel ◽  
True Strain ◽  
Total Elongation ◽  
Recrystallization Annealing

The influence of thermo-mechanical treatment consisting of cold rolling followed by recrystallization annealing on the grain size and mechanical properties of a high-Mn TWIP steel was studied. An Fe-23Mn-0.3C-1.5Al TWIP steel (wt. %) was subjected to extensive cold rolling with a reduction of 80% (true strain of ∼1.6) and then annealed in the temperature interval ranging from 400 to 900 °C during 20 minutes. Recovery processes took place below 500 °C, partial recrystallization was evident at ~550°C and fully recrystallized structure evolved after annealing at 600 °C and higher. The static recovery resulted in a slight decrease in the yield strength from 1400 MPa to 1250 MPa and the ultimate tensile strength from 1540 MPa to 1400 MPa whereas the total elongation of 4% did not changed. The recrystallization development led to a drastic drop of strength and an increase in ductility. The yield strength of 225 MPa, the ultimate tensile strength of 700 MPa and the total elongation of 79% was obtained after annealing at 900 °C. Correspondingly, the grain size increased from 0.2 μm to 6.2 μm with increase in anneal temperature from 550 to 900°C.

scholarly journals Effect of Aluminum on Microstructure and Mechanical Properties of Weld Metal of Q960 Steel

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Zongxuan Zou ◽  
Zhengjun Liu ◽  
Xingyu Ai ◽  
Dan Wu
Keyword(s):  
Tensile Strength ◽  
Weld Metal ◽  
Impact Energy ◽  
Hsla Steel ◽  
Low Carbon Steel ◽  
High Strength ◽  
Low Carbon ◽  
Cored Wire ◽  
Al Content ◽  
The Impact

High-strength low-alloy (HSLA) steel is used in important steel structural members because of its strength and plastic toughness. Q960 steel is HSLA steel obtained by adding an appropriate amount of alloy elements and quenching and tempering treatment on the basis of ordinary low-carbon steel. This kind of steel has strong hardenability due to the alloy elements added. Cold cracks, embrittlement and softening of the heat-affected zone easily occur after welding. In particular, the low-temperature impact toughness cannot meet the requirements and limits its use. In this paper, self-shielded welding is used to adjust the content of aluminum in flux-cored wire. The relationship between weld metal (WM) microstructure and strength and properties was studied by tensile test and impact test, and the influence mechanism of Al content on weld metal microstructure and properties was analyzed. The results show that when the content of Al is 0.21%, the impact energy at 0 °C~−60 °C is the best, the tensile strength can reach 1035 MPA and the number of pores is small. The size of inclusions in WM is mostly less than 1.0 μm Al2O3 spherical oxide. It can become the center of acicular ferrite (AF) and increase the nucleation probability. However, with the increase of Al content, large irregular AlN inclusions are produced, which reduces the tensile strength and impact energy of the welded joint.

Research on the Cold Rolling Mechanical Character of Low Carbon Base Plate Produced by CSP

2012 ◽  
Vol 538-541 ◽  
pp. 1742-1745
Author(s):  
Su Fen Wang ◽  
Yan Peng ◽  
Zhi Jie Li ◽  
Yun Fei Liu
Keyword(s):  
Tensile Strength ◽  
Cold Rolling ◽  
Work Hardening ◽  
Room Temperature ◽  
Cold Deformation ◽  
Low Carbon Steel ◽  
Base Plate ◽  
Low Carbon ◽  
Steel Microstructure ◽  
Test Steel

With cold rolling base plate of low carbon steel by CSP process, the cold deformation experiments were carried out by the two-roller reverse-mill in the laboratory. The work-hardening was studied for different deformation plates through the room temperature tensile and microhardness measured, and the microstructure was also studied after deformation. It was found that the steel yield and tensile strength increased and work-hardening marked with the deformation augment, the test steel microstructure is ferrite with mingle small amount pearlite, its grain is refined and elongated with deformation increasing.

Developing of Mechanical Properties for Reinforcing Bar Steel through Heat Treating with Various Cooling Media

2017 ◽  
Vol 266 ◽  
pp. 267-271
Author(s):  
Muhammad Yunan Hasbi ◽  
Muhammad Budiman ◽  
Bintang Adjiantoro
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Heat Treating ◽  
Martensite Phase ◽  
Low Carbon ◽  
Reinforcing Bar ◽  
Suitable Treatment ◽  
Air Sample ◽  
Cooling Media ◽  
Hot Rolled

In this study, mechanical properties development of reinforcing bar steel (rebar) has examined through heat treatment process. This rebar was made from low carbon lateritic steel with the small amount of alloying elements Cr,Mn and Ni. There were 4 rebar steel samples that consisted of rebar steel was applied hot rolled at 1200 °C at the beginning process in factory (sample A) and three others were conducted by quenching (sample B, C and D). The various of cooling media such as water (sample B), oil (sample C) and air (sample D) have applied to obtain different microstructure behavior and also mechanical properties. Initial heating was conducted to B,C and D rebar specimens at the austenitizing temperature (950 °C) for 1 h and followed by quenching. The experimental results showed that water quench exhibited of higher hardness level (50,26 HRC) for rebar steel but decreasing in toughness (34 Joule) and elongation (4%) than as cast because of martensite phase formed. Sample C showed that martensite and the small amount of retained austenite with hardness and tensile strength below the sample B, but elongation and energy absorbed were above. The lowest of hardness and tensile strength were obtained from sample D. It was appropriate with microstructuree formed as follows ferrite-pearlite phase and widmanstatten-bainite cluster. Nevertheless, sample D is suitable treatment for tensile strength and elongation requirements rebar standard, there are 558 Mpa and 26% respectively (min. 440 MPa and 20%).

Sign in / Sign up

Export Citation Format

Share Document