Preparation and Mechanical Properties of Ultra-Fine Grain Medium-Carbon Steel Based on Equal-Channel Angular Pressing

2015 ◽  
Vol 645-646 ◽  
pp. 427-434
Author(s):  
Jian Min Wang ◽  
Wen Tao Hou ◽  
Lin Lu
Keyword(s):  
Phase Transformation ◽  
Carbon Steel ◽  
Equal Channel Angular Pressing ◽  
Martensitic Steel ◽  
Medium Carbon Steel ◽  
Optimal Size ◽  
Tempering Temperature ◽  
Medium Carbon ◽  
Angular Pressing ◽  
Average Grain Size

A new technology of preparing submicron medium-carbon steel quickly using martensitic steel by equal-channel angular pressing is developed. The technology combines martensite phase transformation with severe plastic deformation. In this research, martensitic steel is heated to 923K quickly and held for appropriate time, then equal-channel angular pressing is implemented. Supersaturated ferrites of average grain size within 0.5μm are obtained by the interaction of dislocation intersection, dynamic recrystallization and strain-induced phase transformation. At the same time, strain-induced phase transformation leads to dispersive precipitation of supersaturated carbon particles in the form of carbide inside grains or in grain boundaries. The optimal size of ferrite grains and the optimal distribution of carbides are acquired by controlling tempering temperature and time. The results show that ultra-fine grained materials prepared by this technology possess superior thermal stability.

Neutron diffraction study of the kinetics of low-temperature martensite decomposition in medium-carbon steel

2021 ◽  
Vol 6 ◽  
pp. 83-87
Author(s):  
A. A. Alekseev ◽  
◽  
S. S. Goncharov ◽  
Keyword(s):  
Solid Solution ◽  
Carbon Steel ◽  
Low Temperature ◽  
Neutron Diffraction ◽  
Supersaturated Solid Solution ◽  
Medium Carbon Steel ◽  
Tempering Temperature ◽  
Medium Carbon ◽  
Temperature Decomposition ◽  
Two Stages

It is found that the low-temperature decomposition of martensite in quenched medium-carbon steel occurs in two stages. In the first stage, the rate of decomposition is higher than that in the subsequent stage. Application of the neutron diffraction method allows the identification of two stages of transformation in the first stage of martensite decomposition. It is shown that the first stage is associated predominantly with carbon segregation at dislocations, and the second, with the outdiffusion of carbon from the supersaturated solid solution with the formation of dispersed particles of metastable carbides. It is shown that the change in the concentration of carbon and, accordingly, the degree of tetragonal lattice of martensite at aging and low tempering occurs to a certain limit, independent of the cooling rate during quenching and tempering temperature. This is due to the establishment of a relative equilibrium between a supersaturated solid solution and fine particles of metastable iron carbide. It is found that the determining process, which leads to a change in the microhardness the low-temperature decomposition, is the out diffusion of carbon from the supersaturated solid solution.

Laser Hardening of Steel

1983 ◽  
Vol 21 ◽  
Author(s):  
B. Bengtsson ◽  
W-B. Li ◽  
K.E. Easterling
Keyword(s):  
Phase Transformation ◽  
Carbon Steel ◽  
Medium Carbon Steel ◽  
Laser Hardening ◽  
Thermal Cycles ◽  
Medium Carbon ◽  
Austenite Transformation ◽  
Theoretical Predictions ◽  
Kinetics Of ◽  
Good Agreement

ABSTRACTChanges in microstructure due to phase transformation are measured for a number of laser-hardening treatments in both an Nb-microalloyed and a medium carbon steel. These measurements are correlated with theoretical predictions of laser thermal cycles and good agreement is obtained. The kinetics of the ferritic/pearlitic→austenite transformation are also discussed.

Study of Phase Transformation of Medium Carbon Steel after Hot Plastic Deformation

2016 ◽  
Vol 258 ◽  
pp. 599-602
Author(s):  
Rostislav Kawulok ◽  
Ivo Schindler ◽  
Petr Kawulok ◽  
Janusz Dänemark ◽  
Petr Opěla ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Phase Transformation ◽  
Carbon Steel ◽  
Medium Carbon Steel ◽  
Transformation Kinetics ◽  
Bainite Transformation ◽  
Cooling Rates ◽  
Hot Plastic Deformation ◽  
Medium Carbon ◽  
Start Temperature

The CCT and DCCT diagrams of steel C60 (with approx. 0.6 % C) were constructed on the basis of dilatation tests with and/or without an influence of the previous deformation and they were then compared, order to make an evaluation of the influence of the previous deformation on the phase transformation kinetics. For the execution of the experiment, the dilatation module of the plastometer Gleeble 3800 was used. The accuracy of the diagrams was faced with metallographic analyses and measurements. The previous deformation expressly retarded a bainite transformation and slightly accelerated ferrite and pearlite transformations. The martensite start temperature was practically not influenced by the previous deformation; however, the applied deformation caused the creation of the martensite at lower cooling rates.

scholarly journals Microstructural and Wear Properties of Annealed Medium Carbon Steel Plate (EN8) Cladded with Martensitic Stainless Steel (AISI410)

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 958
Author(s):  
Shubrajit Bhaumik ◽  
Manidipto Mukherjee ◽  
Parijat Sarkar ◽  
Anish Nayek ◽  
Viorel Paleu
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Carbon Steel ◽  
Base Metal ◽  
Martensitic Stainless Steel ◽  
Medium Carbon Steel ◽  
Wear Properties ◽  
Medium Carbon ◽  
Average Grain Size ◽  
Pin On Disc

Limited work on the wear properties of martensitic stainless-steel weld clads initiated this work which included investigations on microstructural and wear properties of cladded AISI 410 (filler wire)/EN 8 plates (substrate). Three layers of martensitic stainless steel (AISI 410) were deposited using metal inert gas (MIG) welding on medium carbon steel (EN 8) achieving a 51.5 ± 2.35 HRC of top layer. The elemental and phase fractions of the cladded layers indicated 98% martensite phase and retained austenite (2%). About 40% dilution was observed between EN 8 and the first weld layer. The results of tests carried out on pin on disc tribometer revealed an enhancement of anti-wear life of the martensitic weld cladded EN 8 by three times that of uncladded EN 8. The uncladded EN 8 plate suffered severe damage and high wear, leading to its failure at 478 s. The failure of the uncladded EN 8 sample was identified by the occurrence of high vibration of the pin on disc tribometer which ultimately stopped the tribometer. On the other hand, the cladded EN 8 sample continued running for 3600 s, exhibiting normal wear. After the tribo test, the surfaces of the pins of both cladded and uncladded EN 8 were analyzed using scanning electron microscope (SEM) and 3D profilometer. The surface characterization of tribo pairs indicated ploughing and galling to be the primary wear mechanisms. The average grain size of top and middle layer was in the range of 2–3.5 µm, while the base metal showed 5.02 µm mean grain size, resulting in higher hardness of clad layers than base metal, also favoring better wear resistance of the cladded EN 8 samples as compared to uncladded EN 8 samples.

Preparation and Properties of Ultra-Fine Grain Medium-Carbon Steel Based on Warm Deformation

2014 ◽  
Vol 488-489 ◽  
pp. 74-78 ◽  
Author(s):  
Jian Min Wang ◽  
Yan Zhao ◽  
Ke Sheng Cheng ◽  
Li Wan
Keyword(s):  
Carbon Steel ◽  
Grain Boundaries ◽  
Martensitic Steel ◽  
Dislocation Motion ◽  
Medium Carbon Steel ◽  
Warm Deformation ◽  
Medium Carbon ◽  
Fine Grain ◽  
Slip Planes ◽  
Quenched Steel

Combining phase transformation with deformation effectively, a new preparation process of ultra-fine grain medium-carbon steel using martensitic steel was developed. In this research, quenched steel was heated to 500~600 °C quickly, and tempered for an appropriate time to retain a certain degree of supersaturation. Then quick warm deformation was implemented. By the action of twinning, dislocation decomposition, recrystallization, etc., which realizes dislocation motion on slip planes to form dislocation forests or cross-slip, supersaturated ferrites are refined quickly. Strain-induced cementite particles precipitate dispersively in grain boundaries or sub-grain boundaries, and uniform and stable structures are obtained.

The Effect of Controlled Rolling and Cooling on the Microstructure Evolution of Boron Microalloyed Medium-Carbon Steel

2010 ◽  
Vol 146-147 ◽  
pp. 1305-1309
Author(s):  
Wu Hua Yuan ◽  
Qiang Fu ◽  
Heng Zhou
Keyword(s):  
Carbon Steel ◽  
Grain Boundaries ◽  
Microstructure Evolution ◽  
Volume Fraction ◽  
Controlled Rolling ◽  
Medium Carbon Steel ◽  
Rolling Temperature ◽  
Compression Tests ◽  
Medium Carbon ◽  
Average Grain Size

The processes of controlled rolling and cooling were simulated using hot compression tests on a Gleeble 1500 simulator with boron microalloyed medium-carbon steel. Effects of finish rolling temperature ranging from 760oC to 840oC and loop-laying temperature ranging from 660oC to 700oC on the microstructure evolution were studied. Experimental observations show that the average grain size of ferrite decreases while the volume fractions of ferrite and spheroidized pearlite increase when lowering rolling temperature. The maximum volume fraction of ferrite (62%) reached in our tests was obtained in the specimen whose rolling temperature and loop-laying temperature was 760oC and 700oC respectively. Excessive precipitation of the ferrite resulted in the carbon enrichment on some grain boundaries. Boron addition is effective to improve hot plastic deformation ability by removing nitrogen from AlN to form coarse BN particles on the grain boundaries.

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