scholarly journals Influence of laser heat treatment on microstructure and properties of surface layer of Waspaloy aimed for laser-assisted machining

2017 ◽  
Vol 93 (9-12) ◽  
pp. 3111-3123 ◽  
Author(s):  
Damian Przestacki ◽  
Mateusz Kukliński ◽  
Aneta Bartkowska
Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 379 ◽  
Author(s):  
Wei Zhang ◽  
Tao Jiang ◽  
Jing Li ◽  
Liqiang Liu

The effects of laser heat treatment on the microstructure and properties of alloy 800H were investigated. The fracture morphology, elemental changes, and phase composition of the specimens were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffractometry (XRD). The results show that the long-lasting life of the specimen after laser heat treatment increased by 28.6%, and the elongation after fracture increased by 20.7%. The macroscopic morphology of the fracture specimen exhibited obvious ductile fracture morphology, and the changes in the elemental content and grain size significantly affected the ductility and toughness of the alloy. This study has certain guiding significance for the optimization of the heat treatment process of this type of alloy.


2012 ◽  
Vol 57 (1) ◽  
pp. 211-214 ◽  
Author(s):  
A. Bartkowska ◽  
A. Pertek ◽  
M. Jankowiak ◽  
K. Jóźwiak

Laser Surface Modification of Borochromizing C45 SteelIn this study the test results for borochromized C45 steel after laser surface modification were presented. Influence of laser heat treatment on the microstructure and microhardness of surface layer was investigated. The process of borochromizing consisted of chromium plating followed by diffusion boronizing. The laser heat treatment (LHT) of multiple tracks in the helical line was carried out with CO2laser beam. The technological laser TRUMPF TLF 2600 Turbo CO2of the nominal power 2.6 kW was applied. Borochromizing was carried out with laser power density q = 41.40 kW/cm2and at laser beam scanning rate v = 0.67 m/min and v = 2.016 m/min. Measurements of microhardness were conducted using the Vickers' method and Zwick 3212 B hardness tester. Microstructure observations were performed by means of an optical microscope Metaval Carl Zeiss Jena and scanning electron microscope Tescan VEGA 5135. After laser heat treatment with re-melting a three-zone layer was obtained, which included: re-melted zone, heat affected zone and a core. Influence of laser treatment parameters on thickness of melted zone and microstructure of the surface layer was tested. The microhardness tested along the axis of track of the surface layer after laser modification was about 800-850 HV. The results of tests showed influence of laser power density and scanning rate on microstructure and properties of borochromized layers.


2021 ◽  
Vol 6 (1 (114)) ◽  
pp. 72-80
Author(s):  
Oleksandr Danyleiko ◽  
Vitaliy Dzhemelinskyi ◽  
Dmytro Lesyk

A technique is presented for hardening metal products, in particular, the main tools (hammers) and cases of core drilling bits made of steel 30HGSA, using thermomechanical surface treatment according to a separate scheme. The method of combined laser thermomechanical hardening used in the study consists in the use of shot peening followed by laser heat treatment. Its use makes it possible to increase the operational properties of steel products, in particular, their wear and corrosion resistance. Based on the results of theoretical and experimental studies, the paper substantiates the features of dynamic surface plastic deformation for the analysis of impact during shot peening. The advantages of using laser hardening without surface melting are presented. Experimental research methods are proposed for determining the structural-phase composition, structure of the surface layer, hardness and microhardness of the hardened zones of steel 30HGSA. The range of rational modes of impact shot peening and thermal laser treatment has been determined. A device for testing samples for wear resistance has been developed. Methods of testing for wear and corrosion resistance of the surface of samples are proposed for assessing the tribological properties and contact interaction of materials under quasi-static and dynamic loading conditions. It is concluded that rational technological modes of hardening tools made of steel 30HGSA using combined laser thermomechanical treatment allow increasing the depth of the hardened layer by ~1.5 times compared to laser heat treatment. In addition, they provide the microhardness of the surface layer of ~5400 MPa, which is ~2.5 times higher than the microhardness of the base material


Author(s):  
I. Bauer ◽  
M. Paczkowska

Purpose: This paper presents the findings of a study of laser heat treatment of C45 steel following diffusion chromizing. The aim of the study was to assess the effect of laser heating of steel subjected on the microstructure of its surface layer. Design/methodology/approach: Diffusion chromizing was conducted at the temperature of 1050°C for 8 hours in a LABOTHERM LH15/14 laboratory furnace. A powder mixture of the following composition was used to produce the layer: Cr2O3 with an addition of Al, kaolin and an activator – ammonium chloride NH4Cl. Diffusion chromizing of C45 steel was followed by laser heat treatment with a dual diode TRUDISK 1000 laser device. The treatment was carried out in four variants with a laser beam of 400 to 900 W. The microstructure of the surface layer was assessed with a scanning electron microscope Tescan Vega 5135. Hardness tests were carried out by the Vickers method on crosswise microsections. The chemical composition of the diffusion layer was assessed by optical emission spectrometry. Findings: The results revealed the presence of a modified surface layer following laser heat treatment in each of the variants. Research limitations/implications: This study focuses on the effect of laser heating of C45 steel subjected to diffusion chromizing on the microstructure of its top layer. Presented research are the first step of the investigation of the surface layer of steel after diffusion chromizing and laser treatment. Next one will be consisted in detailed investigation of microstructure (phases identification) of the achieved surface layer using (among other methods) X-ray diffraction. Practical implications: Laser heat treatment of C45 steel after diffusion chromizing can be applied to parts of machines and devices used in various branches of industry exposed to tribological wear and corrosion. Originality/value: The results of the experiment were affected by the composition of the powder mixture and process parameters of the diffusion chromizing and the laser treatment.


Author(s):  
Rachid Fakir ◽  
Noureddine Barka ◽  
Jean Brousseau

This paper presents a numerical model able to control the temperature distribution along a 4340 steel cylinder heat-treated with Nd: YAG laser. The numerical model developed using the numerical finite element method, was based on a study of surface temperature variation and the adjustment of this temperature by a control of the heat treatment laser power. The proposed analytical approach was built gradually by (i) the development of a numerical model of laser heat treatment of the cylindrical workpiece, (ii) an analysis of the results of simulations and experimental tests, (iii) development of a laser power adjustment approach, and (iv) proposal of a laser power control predictor using neural networks. This approach was made possible by highlighting the influence of the fixed (non-variable) parameters of the laser heat treatment on the case depth, and has shown that it is possible by controlling the laser parameters to homogenize the distribution of the maximum temperature reached on the surface for a uniform case depth. The feasibility and effectiveness of the proposed approach leads to a reliable and accurate model able to guarantee a uniform surface temperature and a regular case depth for a cylindrical workpiece of a length of 50-mm and with a diameter of between 16-mm and 22-mm.


2010 ◽  
Author(s):  
Byungki Jung ◽  
Jing Sha ◽  
Florencia Paredes ◽  
Christopher K. Ober ◽  
Michael O. Thompson ◽  
...  

2019 ◽  
Vol 743 ◽  
pp. 294-300 ◽  
Author(s):  
Kun Wang ◽  
Aiping Wei ◽  
Zimu Shi ◽  
Xizhang Chen ◽  
Jixing Lin ◽  
...  

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