Study of Nano-Precipitate in High Strength Low Carbon Steel during Tempering by TEM

2013 ◽  
Vol 327 ◽  
pp. 123-127 ◽  
Author(s):  
Long Fei Zuo ◽  
Li Li Qiu ◽  
Bin Hou ◽  
Xiao Hua Chen ◽  
Ming Wen Chen ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Energy Dispersive Spectrometry ◽  
Low Carbon Steel ◽  
High Strength ◽  
Growing Up ◽  
Low Carbon ◽  
Tempering Temperature ◽  
Transmission Electron ◽  
The Matrix ◽  
Oswald Ripening

The behavior of nanoprecipitates of 800Mpa grade high strength low carbon steel during tempering has been studied. Transmission electron microscope (TEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive spectrometry (EDS) were used to systematically analyze the morphology of precipitates and their grain orientation with matrix at different tempering temperatures. Experimental results confirm that the composition of these nanometer sized particles in the matrix was compound carbonitrides containing Ti, V, Mo and other elements. The precipitates of the as-received steel are (Nb,Ti)(C,N) at low tempering temperature, while those at high tempering temperature are composite carbides containing a variety of elements such as Mo, V, Ti and Nb. On the other hand, as tempering temperature increases, precipitates in the steel were slowly growing up and roughening according with the typical Oswald ripening mechanism; a sharp orientation relationship exists between precipitates and matrix.

An Exceptional Synergy of High Strength, Ductility and Toughness in a Gradient-Structured Low-Carbon Steel

2018 ◽  
Vol 27 (11) ◽  
pp. 5788-5793
Author(s):  
Yindong Shi ◽  
Lina Wang ◽  
Yulong Zhang ◽  
Hailong Xie ◽  
Yajun Zhao
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
High Strength ◽  
Low Carbon

Corrosion Behavior of Al-Si-Cr-Cu Bearing Low Carbon Steel in A Cyclic Dry/Wet Laboratory Test

2009 ◽  
Vol 79-82 ◽  
pp. 1017-1020 ◽  
Author(s):  
Hui Shu Zhang ◽  
Dong Ping Zhan ◽  
Song Lian Bai ◽  
Zhou Hua Jiang
Keyword(s):  
Carbon Steel ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Optical Microscope ◽  
Low Carbon ◽  
Rust Layer ◽  
Electrochemical Behaviors ◽  
Corrosion Rates ◽  
The Matrix ◽  
Corrosion Behaviors

The corrosion behaviors of Al-Si-Cr-Cu bearing low carbon steel and a reference steel Q235 were tested in a cyclic dry/wet environment containing 0.01mol/L NaHSO3 in laboratory. Rust layers were observed by optical microscope (OM), scanning electron microscopy (SEM) and XRD. The electrochemical behaviors of the steels were studied on the polarization curves and electrochemical impedance spectroscopy (EIS). The results indicate that after 120h corrosion test, the annual corrosion rates of the designed steels reduce 42 % than Q235 at least. The corrosion products are generally iron oxyhydroxides and oxides such as FeOOH, γ-FeOOH, α-FeOOH, γ-Fe2O3, Fe3O4. The α-FeOOH possesses good stabilization mainly exits and can improve the corrosion resistance. There are the enrichments of Cu, Cr, Si and Al in the rust layer close to the matrix, which make the rust layer be more compact and protected. The corrosion currents of the two designed steels are lower than that of Q235, the corrosion potentials are higher than that of Q235 after Tafel fitting. The rust layer impedances of the designed steels are higher than that of Q235.

Interfacial segregation at Cu-rich precipitates in a high-strength low-carbon steel studied on a sub-nanometer scale

2006 ◽  
Vol 54 (3) ◽  
pp. 841-849 ◽  
Author(s):  
Dieter Isheim ◽  
Michael S. Gagliano ◽  
Morris E. Fine ◽  
David N. Seidman
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
High Strength ◽  
Nanometer Scale ◽  
Low Carbon ◽  
Interfacial Segregation

scholarly journals Quantitative Description of External Force Induced Phase Transformation in Silicon–Manganese (Si–Mn) Transformation Induced Plasticity (TRIP) Steels

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3781
Author(s):  
Zhongping He ◽  
Huachu Liu ◽  
Zhenyu Zhu ◽  
Weisen Zheng ◽  
Yanlin He ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Carbon Steel ◽  
Trip Steel ◽  
Retained Austenite ◽  
Low Carbon Steel ◽  
High Strength ◽  
High Plasticity ◽  
Low Carbon ◽  
Transformation Induced Plasticity ◽  
Trip Steels

Transformation Induced Plasticity (TRIP) steels with silicon–manganese (Si–Mn) as the main element have attracted a lot of attention and great interest from steel companies due to their low price, high strength, and high plasticity. Retained austenite is of primary importance as the source of high strength and high plasticity in Si–Mn TRIP steels. In this work, the cold rolled sheets of Si–Mn low carbon steel were treated with TRIP and Dual Phase (DP) treatment respectively. Then, the microstructure and composition of the Si–Mn low carbon steel were observed and tested. The static tensile test of TRIP steel and DP steel was carried out by a CMT5305 electronic universal testing machine. The self-built true stress–strain curve model of TRIP steel was verified. The simulation results were in good agreement with the experimental results. In addition, the phase transformation energy of retained austenite and the work borne by austenite in the sample during static stretching were calculated. The work done by austenite was 14.5 J, which was negligible compared with the total work of 217.8 J. The phase transformation energy absorption of retained austenite in the sample was 9.12 J. The role of retained austenite in TRIP steel is the absorption of excess energy at the key place where the fracture will occur, thereby increasing the elongation, so that the ferrite and bainite in the TRIP steel can absorb energy for a longer time and withstand more energy.

scholarly journals Effect of Carbon Partitioning, Carbide Precipitation, and Grain Size on Brittle Fracture of Ultra-High-Strength, Low-Carbon Steel after Welding by a Quenching and Partitioning Process

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 747 ◽  
Author(s):  
Farnoosh Forouzan ◽  
M. Guitar ◽  
Esa Vuorinen ◽  
Frank Mücklich
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Weld Zone ◽  
Low Carbon Steel ◽  
High Strength ◽  
Precipitate Size ◽  
Low Carbon ◽  
Quenching And Partitioning ◽  
High Level ◽  
The Impact

To improve the weld zone properties of Advanced High Strength Steel (AHSS), quenching and partitioning (Q&P) has been used immediately after laser welding of a low-carbon steel. However, the mechanical properties can be affected for several reasons: (i) The carbon content and amount of retained austenite, bainite, and fresh martensite; (ii) Precipitate size and distribution; (iii) Grain size. In this work, carbon movements during the partitioning stage and prediction of Ti (C, N), and MoC precipitation at different partitioning temperatures have been simulated by using Thermocalc, Dictra, and TC-PRISMA. Verification and comparison of the experimental results were performed by optical microscopy, X-ray diffraction (XRD), Scanning Electron Microscop (SEM), and Scanning Transmission Electron Microscopy (STEM), and Energy Dispersive Spectroscopy (EDS) and Electron Backscatter Scanning Diffraction (EBSD) analysis were used to investigate the effect of martensitic/bainitic packet size. Results show that the increase in the number density of small precipitates in the sample partitioned at 640 °C compensates for the increase in crystallographic packets size. The strength and ductility values are kept at a high level, but the impact toughness will decrease considerably.

scholarly journals Impact of Cold-Rolling and Heat Treatment on Mechanical Properties of Dual-Phase Treated Low Carbon Steel

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Le Van Long ◽  
Dinh Van Hien ◽  
Nguyen Truong Thanh ◽  
Nguyen Chi Tho ◽  
Van Thom Do
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
High Strength ◽  
Processing Parameters ◽  
Dual Phase ◽  
Low Carbon ◽  
Forming Process ◽  
Good Ductility ◽  
Rolling Deformation

The low carbon steel has good ductility that is favorable for forming process, but its low strength leads to limiting their application for forced structures. This paper studied improving strength of low-carbon steel via rolling deformation and dual-phase treatment. The results showed that the dual-phase treated steel had a combination of high strength and good ductility; its tensile ultimate strength reached 740 MPa with elongation at fracture of over 15%, while that of the cold-rolled steel only reached 700 MPa with elongation at fracture of under 3%. Based on the obtained results, relationships between mechanical properties and dual-phase processing parameters were established to help users choose suitable-processing parameters according to requirements of products.

High strength state in low carbon steel with submicron fibrous structure

1996 ◽  
Vol 206 (1) ◽  
pp. 39-44 ◽  
Author(s):  
A.V. Korznikov ◽  
I.M. Safarov ◽  
A.A. Nazarov ◽  
R.Z. Valiev
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
High Strength ◽  
Fibrous Structure ◽  
Low Carbon

Reliability Increase of Dissimilar Steel Welded Joints

2014 ◽  
Vol 698 ◽  
pp. 378-381 ◽  
Author(s):  
Alexandra Chevakinskaya ◽  
Aelita Nikulina ◽  
Natalia Plotnikova
Keyword(s):  
Carbon Steel ◽  
Welded Joints ◽  
Rail Steel ◽  
High Carbon Steel ◽  
Low Carbon Steel ◽  
High Strength ◽  
Hadfield Steel ◽  
Nickel Steel ◽  
Low Carbon ◽  
High Carbon

In this paper combined Hadfield steel - stainless steel - rail steel compounds are considered. Structural studies and estimation of mechanical properties showed that using an intermediate layer of low-carbon steel with 0.2 C wt. % and 5-20 mm thick between high-carbon steel and chromium-nickel steel in the formation of welded joints increases the reliability of connections by reducing the amount of high-strength zones as compared to compounds without a barrier layer.

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