Calculation of residual stresses induced during laser quench-hardening of steel

Residual stresses are critical to the fatigue performance of parts. In general, compressive residual stress in the surface is beneficial, and residual tension is detrimental because of the effect of stress on crack initiation and propagation. Carburization and quench hardening create compressive residual stresses in the surface of steel parts. The laser peening process has been successfully used to introduce residual compression to the surface of nonferrous alloy parts. However, the application on carburized steel parts has not been successful so far. The application of laser peening on carburized steel parts is limited due to two main reasons: 1) the high strength and low ductility of carburized case, and 2) the compressive residual stresses in the surface of the part prior to laser peening. In this paper, the carburization, quench hardening, and laser peening processes are integrated using finite element modeling. The predicted residual stresses from quench hardening and laser peening are validated against residual stresses determined from X-ray diffraction measurements. An innovative concept of laser peening with preload has been invented to enhance the residual compression in a specific region of laser peened parts. This concept is proved by FEA models using DANTE-LP.

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Method to evaluate residual stresses in the laser cutting process

Lasers in Engineering ◽

10.1080/08981500290022752 ◽

2002 ◽

Vol 12 (1) ◽

pp. 27-41 ◽

Cited By ~ 7

Author(s):

Y. Zamachtchikov ◽

F. Breaban ◽

P. Vantomme ◽

A. Deffontaine

Keyword(s):

Residual Stresses ◽

Laser Cutting ◽

Cutting Process

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Prediction of residual stresses and springback after bending of a textured aluminium plate

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:20030185 ◽

2003 ◽

Vol 105 ◽

pp. 175-182 ◽

Cited By ~ 2

Author(s):

L. Delannay ◽

R. E. Logé ◽

Y. Chastel ◽

P. Van Houtte

Keyword(s):

Residual Stresses

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Theoretical study of the prestressing strand's stress by computer modeling methods

Ferrous Metallurgy Bulletin of Scientific Technical and Economic Information ◽

10.32339/0135-5910-2020-111-1139-1148 ◽

2020 ◽

Vol 76 (11) ◽

pp. 1139-1148

Author(s):

A. G. Korchunov ◽

E. M. Medvedeva ◽

E. M. Golubchik

Keyword(s):

Residual Stresses ◽

High Strength ◽

Pearlitic Steel ◽

Internal Stresses ◽

Steel Microstructure ◽

Compressive Stresses ◽

Wide Range ◽

Prestressing Strands ◽

Increasing Temperature ◽

Wire Strand

The modern construction industry widely uses reinforced concrete structures, where high-strength prestressing strands are used. Key parameters determining strength and relaxation resistance are a steel microstructure and internal stresses. The aim of the work was a computer research of a stage-by-stage formation of internal stresses during production of prestressing strands of structure 1х7(1+6), 12.5 mm diameter, 1770 MPa strength grade, made of pearlitic steel, as well as study of various modes of mechanical and thermal treatment (MTT) influence on their distribution. To study the effect of every strand manufacturing operation on internal stresses of its wires, the authors developed three models: stranding and reducing a 7-wire strand; straightening of a laid strand, stranding and MTT of a 7-wire strand. It was shown that absolute values of residual stresses and their distribution in a wire used for strands of a specified structure significantly influence performance properties of strands. The use of MTT makes it possible to control in a wide range a redistribution of residual stresses in steel resulting from drawing and strand laying processes. It was established that during drawing of up to 80% degree, compressive stresses of 1100-1200 MPa degree are generated in the central layers of wire. The residual stresses on the wire surface accounted for 450-500 MPa and were tension in nature. The tension within a range of 70 kN to 82 kN combined with a temperature range of 360-380°С contributes to a two-fold decrease in residual stresses both in the central and surface layers of wire. When increasing temperature up to 400°С and maintaining the tension, it is possible to achieve maximum balance of residual stresses. Stranding stresses, whose high values entail failure of lay length and geometry of the studied strand may be fully eliminated only at tension of 82 kN and temperature of 400°С. Otherwise, stranding stresses result in opening of strands.

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