scholarly journals Microstructure of Fe–TiC Composite Surface Layer on Carbon Steel Formed by Laser Alloying Process

2013 ◽  
Vol 54 (9) ◽  
pp. 1755-1759 ◽  
Author(s):  
Takuto Yamaguchi ◽  
Hideki Hagino ◽  
Mamoru Takemura ◽  
Yasunori Hasegawa ◽  
Yasuhiro Michiyama ◽  
...  
Author(s):  
J Radziejewska

The results of experimental research on the influence of laser alloying parameters on the structure and chemical composition are presented. The alloying process was performed with a continuous CO2 laser, of a 2.5 kW power, at different densities of energy and different interaction times of beam on material. The experiments were done on carbon steel, which was alloyed with powders of tungsten carbide and cobalt stellite. The microstructure, the distribution of alloyed elements, and the microhardness of the surface layer were studied after a laser alloying process. It was shown that alloying layer morphology depends on the laser alloying parameters, especially on interaction time. The research has verified that the motion process of liquid material determines the alloyed layer morphology and indicates a necessity to take into account the convection process.


2010 ◽  
Vol 649 ◽  
pp. 101-106
Author(s):  
Mária Svéda ◽  
Dóra Janovszky ◽  
Kinga Tomolya ◽  
Jenő Sólyom ◽  
Zoltán Kálazi ◽  
...  

The aim of our research was to comparatively examine Ni content surface layers on amorphisable Cu base alloy produced by different laser surface treatments. Laser surface treatment (LST) techniques, such as laser surface melting, laser alloying and laser cladding, provide a wide range of interesting solutions for the production of wear and corrosion resistant surfaces. [1,2] With LST techniques, the surface can be: i) coated with a layer of another material by laser cladding, ii) the composition of the matrix can be modified by laser alloying. [3] Two kinds of laser surface treatment technologies were used. In the case of coating-melting technology a Ni content surface layer was first developed by galvanization, and then the Ni content layer was melted together with the matrix. In the case of powder blowing technology Ni3Al powder was blown into the layer melted by laser beam and Argon gas. LST was performed using an impulse mode Nd:YAG laser. The laser power and the interaction time were 2 kW and 20÷60 ms. The characterization of the surface layer microstructure was performed by XRD, scanning electron microscopy and microhardness measurements.


2001 ◽  
Vol 44 (8-9) ◽  
pp. 1791-1795 ◽  
Author(s):  
G Liu ◽  
S.C Wang ◽  
X.F Lou ◽  
J Lu ◽  
K Lu

2013 ◽  
Vol 27 (11) ◽  
pp. 903-906 ◽  
Author(s):  
V.I. Ivanov ◽  
F.Kh. Burumkulov ◽  
A.D. Verkhoturov ◽  
P.S. Gordiyenko ◽  
Ye.S. Panin ◽  
...  

2013 ◽  
Vol 29 (5) ◽  
pp. 331-335 ◽  
Author(s):  
P Zhang ◽  
F C Zhang ◽  
Z G Yan ◽  
C L Zheng
Keyword(s):  

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 995
Author(s):  
Haitao Xiao ◽  
Shaobo Zheng ◽  
Yan Xin ◽  
Jiali Xu ◽  
Ke Han ◽  
...  

Surface hardening improves the strength of low-carbon steel without interfering with the toughness of its core. In this study, we focused on the microstructure in the surface layer (0–200 μm) of our low-carbon steel, where we discovered an unexpectedly high level of hardness. We confirmed the presence of not only upper bainite and acicular ferrite but also lath martensite in the hard surface layer. In area of 0–50 μm, a mixed microstructure of lath martensite and B1 upper bainite was formed as a result of high cooling rate (about 50–100 K/s). In area of 50–200 μm, a mixed microstructure of acicular ferrite and B2 upper bainite was formed. The average nanohardness of the martensite was as high as 9.87 ± 0.51 GPa, which was equivalent to the level reported for steel with twenty times the carbon content. The ultrafine laths with an average width of 128 nm was considered to be a key cause of high nanohardness. The average nanohardness of the ferrites was much lower than for martensite: 4.18 ± 0.39 GPa for upper bainite and 2.93 ± 0.30 GPa for acicular ferrite. Yield strength, likewise, was much higher for martensite (2378 ± 123 MPa) than for upper bainite (1007 ± 94 MPa) or acicular ferrite (706 ± 72 MPa). The high yield strength value of martensite gave the surface layer an exceptional resistance to abrasion to a degree that would be unachievable without additional heat treatment in other steels with similar carbon content.


Tribologia ◽  
2019 ◽  
Vol 288 (6) ◽  
pp. 73-80
Author(s):  
Aleksandra Pertek-Owsianna ◽  
Karolina Wiśniewska-Mleczko ◽  
Adam Piasecki

This paper presents two methods of introducing boron into the surface layer of iron alloys, namely diffusion boronizing by means of the powder method and laser alloying with a TRUMPF TLF 2600 Turbo CO2 gas laser. Amorphous boron was used as the chemical element source. As regards diffusion drilling, the influence of temperature and time on the properties of the layer was tested. During the laser alloying, the influence of the thickness of the boriding paste layer as well as the power and laser beam scanning velocity was determined. How the carbon content in steel and alloying elements in the form of chromium and boron influence the structure of the surface layer was tested. To achieve this object, the following grades of steel were used: C45, C90, 41Cr4, 102Cr6, and HARDOX boron steel. The microhardness and wear resistance of the obtained boron-containing surface layers were tested. A Metaval Carl Zeiss Jena light microscope and a Tescan VEGA 5135 scanning electron microscope, a Zwick 3212B microhardness tester, and an Amsler tribotester were used for the tests. The structure of the diffusion- borided layer consists of the needle-like zone of FeB + Fe2B iron borides about 0.15 mm thick, with a good adhesion to the substrate of the steel subjected to hardening and tempering after the boriding process. After the laser alloying, the structure shows paths with dimensions within: width up to 0.60 mm, depth up to 0.35 mm, containing a melted zone with a eutectic mixture of iron borides and martensite, a heat affected zone with a martensitic-bainitic structure and a steel core. The microhardness of both diffusionborided and laser-borided layers falls within the range of 1000 – 1900 HV0.1, depending on the parameters of the processes. It has been shown that, apart from the structure and thickness of the layer containing boron and microhardness, the frictional wear resistance depends on the state of the steel substrate, i.e. its chemical composition and heat treatment. The results of testing iron alloys in the borided state were compared with those obtained only after the heat treatment.


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