Laser Hardening of Steel

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.

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A study of the dynamic recrystallization kinetics of V-microalloyed medium carbon steel

Journal of Materials Science ◽

10.1007/s10853-015-9171-1 ◽

2015 ◽

Vol 50 (18) ◽

pp. 6142-6153 ◽

Cited By ~ 4

Author(s):

K. W. Kim ◽

J. K. Park

Keyword(s):

Carbon Steel ◽

Dynamic Recrystallization ◽

Medium Carbon Steel ◽

Medium Carbon ◽

Recrystallization Kinetics ◽

Kinetics Of

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.645-646.427 ◽

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.

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

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.258.599 ◽

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.

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