Effect of laser surface hardening on the microstructure, hardness and residual stresses of austempered ductile iron grades

Soriano, Carlos; Leunda, Josu; Lambarri, Jon; Navas, V. García; Sanz, C.

doi:10.1016/j.apsusc.2011.03.059

Cited by 95 publications

(37 citation statements)

References 5 publications

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“…But the most effective method is increasing laser beam size at the focal plane. Using laser beam shaping technology, a large-sized Gaussian beam [13], a wide-band beam [8], and a rectangular beam [7] were designed to get a wider single hardened layer. To get a relatively more uniform hardened layer, a customized beam with a slope intensity profile [14] and an M-shaped laser beam profile [9] were proposed and theoretically investigated.…”

Section: Introductionmentioning

confidence: 99%

Laser surface hardening of 42CrMo cast steel for obtaining a wide and uniform hardened layer by shaped beams

Sun

et al. 2013

Int J Adv Manuf Technol

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For laser surface hardening (LSH) of large-sized workpieces, a wide and uniform hardened layer of a single track is pursued. In this study, two kinds of shaped laser beams were used in LSH of 42CrMo cast steel to obtain the required hardened layer. One is a stripy spot with uniform-intensity array spots and the other a stripy spot with intensity blowup in the edge of the whole array spots. As a comparison, a Gaussian laser beam was also adopted. A three-dimensional finite element model was used to simulate the thermal history of specific points by the latter shaped beam and the Gaussian laser beam. The surface morphology, microstructure, microhardness, and uniformity of hardened layers were studied. The results showed that a wider and more uniform hardened layer could be obtained using the latter shaped beam at relative higher scanning velocities and laser power. The thermal history of a material has an important effect on the microstructure and microhardness finally formed. Due to the high peak temperature and heating rate caused by the latter shaped beam, a higher value of microhardness in the transformation hardened zone was found.

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Section: Introductionmentioning

confidence: 99%

Laser surface hardening of 42CrMo cast steel for obtaining a wide and uniform hardened layer by shaped beams

Sun

et al. 2013

Int J Adv Manuf Technol

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“…It is predictable that varying the parameters of the laser treatments, the dimension of the treated zones have changed [7][8][9][10]. The dimension of the hardened bands can be seen in the Fig.…”

Section: Resultsmentioning

confidence: 99%

Residual Stress Distribution Caused by Laser Hardening and Conventional Quenching in Plain Carbon Steel

Filep

Benke

Mertinger

et al. 2014

AMR

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Heat transfer during laser hardening occurs from the surface towards the bulk in contrast to conventional quenching, where it occurs from the bulk towards the surrounding. The residual stress distributions due to laser hardening and conventional quenching of plain carbon steel samples were measured using X-ray diffraction. The effect of changing the treatment parameters, that is laser power and feed rate, was examined on the resulting stress distribution. The relationship between the measured stress distribution and the evolved microstructure is established.

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“…Лазерные комплексы, оснащенные волокон-ными и другими лазерами мощностью 1-6 кВт, могут выполнять операции по закалке деталей из конструкционных сталей и чугунов с глуби-ной слоя 1,0-2,0 мм [9][10][11][12][13]. Однако конструкция портальных систем для резки, которые в слу-чае простоя можно использовать для лазерного упрочнения, как правило, не позволяет пере-мещать оптическую головку по высоте более чем на 100 мм.…”

Section: Study Techniqueunclassified

“…The laser complexes equipped with fiber and other lasers with power of 1-6 kW can carry out operations of hardening of parts from constructional steel and cast iron with depth of layer by 1.0-2.0 mm [9][10][11][12][13]. до 9 мм/с и мощности лазера до 1 130 Вт получена зона упрочнения с глубиной 0,68 мм, и твердо-стью 515 HV.…”

Section: Vpbirukov Candidate Of Technical Sciences a Ablagonravmentioning

confidence: 99%

Computational and Experimental Determination of Hard Band Areas Parameters for Laser Hardening of Cast Iron and Steel

Birukov¹

2017

FRos

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Технология лазерного термоупрочнения чугунов и сталей повышает твердость, износостойкость и задиростойкость рабочих поверхностей трения. Представлены результаты испытаний и эксплуатации пары трения, прошедшей лазерное термоупрочнение, в сравнении с традиционными технологиями упрочнения. Выявлены условия и режимы лазерной обработки, снижающие негативное влияние зон отпуска и повышающие производительность лазерной закалки в 1,6-2,5 раза. П ри назначении режимов лазерного терми-ческого упрочнения (ЛТУ) поверхностей трения деталей машин необходимо учи-тывать условия их эксплуатации, механические и теплофизические свойства исходных матери-алов. Производительность лазерной обработки определяется глубиной и площадью упрочнен-ной поверхности. Для повышения износостойко-сти втулки дизеля в два раза достаточно упроч-нить 25% площади рабочей поверхности зеркала цилиндра. Задиростойкость цилиндропоршне-вой группы при этом повышается в 1,8 раза [1]. Экспериментально было установлено, что при упрочнении 50% поверхности трения образцов стали 45, 40Х при испытании на машине тре-ния возвратно-поступательного движения МТВ-1 в паре с контробразцом из чугуна СЧ20 износо-стойкость повышается в 3 раза, а при 100%-ном упрочнении -в 3,3 раза по сравнению с неупроч-ненными образцами [2]. По задиростойкости закаленные лазером образцы не уступает азоти-рованным сталям 40Х и 12ХН3А и значительно -в 1,7 раза -превосходят цементованнную сталь The technology of laser thermal hardening of cast iron and steel increases the hardness, wear resistance and scoring resistance of functional surfaces of friction. The results of tests and operation of friction couple which has passed laser thermal hardening are given in comparison with traditional technologies of hardening. The conditions and the modes of laser processing reducing negative impact of drawingback areas and increasing the effectiveness of laser hardening by 1.6-2.5 times are revealed. W hen assigning the modes of laser thermal hardening (LTH) of friction surfaces of machine parts, it is necessary to consider the conditions of their operation, mechanical and thermo-physical properties of initial materials. The effectiveness of laser processing is defined by depth and the area of the hardened surface. In order to increase wear resistance of the diesel liner by two times, it is enough to harden 25% of the effective area of cylinder bearing surface. The scoring resistance of cylinder-piston group thus increases by 1.8 times [1]. It has been established experimentally that when hardening 50% of friction surface of the samples made of steel 45, 40H when testing on friction machine of reciprocating motion MTV-1 together with counter sample made of cast iron SC20, wear resistance increases by 3 times, and when hardening is 100% -by 3.3 times in comparison with not hardened samples [2]. According to scoring resistance, laser-hardened samples do not concede to nitrated steel 40X and 12HN3A and considerably exceed cemented steel 18HGT by 1.7 times. For laser hardening of steels 45 and 40H with diame...

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Effect of laser surface hardening on the microstructure, hardness and residual stresses of austempered ductile iron grades

Cited by 95 publications

References 5 publications

Laser surface hardening of 42CrMo cast steel for obtaining a wide and uniform hardened layer by shaped beams

Laser surface hardening of 42CrMo cast steel for obtaining a wide and uniform hardened layer by shaped beams

Residual Stress Distribution Caused by Laser Hardening and Conventional Quenching in Plain Carbon Steel

Computational and Experimental Determination of Hard Band Areas Parameters for Laser Hardening of Cast Iron and Steel

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