Amorphisation of Zr60Al15Ni25 surface layers by laser processing for corrosion resistance

1997 ◽  
Vol 37 (4) ◽  
pp. 523-527 ◽  
Author(s):  
D. Carvalho ◽  
S. Cardoso ◽  
R. Vilar
Keyword(s):  
Corrosion Resistance ◽  
Laser Processing ◽  
Surface Layers

scholarly journals The use of laser radiation to increase the efficiency of nitriding processes

2021 ◽  
Author(s):  
Alnusirat Walid ◽  
Leonid Golovko ◽  
Viktor Romanenko ◽  
Mikhailo Bloshchytsyn
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Laser Processing ◽  
Metal Alloys ◽  
Surface Layers ◽  
High Quality ◽  
Combined Process ◽  
Radical Reduction ◽  
Increase Wear Resistance ◽  
Time And Energy

In this study, the technology of laser processing is tested. This combined process of laser chemical-thermal treatment allows by modifying the structures of the surface layers of metal alloys to significantly increase the thickness range of high-quality nitrided layers with a radical reduction in time and energy consumption of the process, significantly expand their applications to increase wear resistance, corrosion resistance and other performance characteristics.

scholarly journals Characteristics of Cr-B Coatings Produced on Vanadis® 6 Tool Steel Using Laser Processing

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2621
Author(s):  
Aneta Bartkowska
Keyword(s):  
Corrosion Resistance ◽  
Tool Steel ◽  
Laser Processing ◽  
Chemical Elements ◽  
Steel Substrate ◽  
Processing Parameters ◽  
Beam Power ◽  
Laser Beam Power ◽  
High Microhardness ◽  
The Impact

The paper presents the results of a study of the microstructure, chemical composition, microhardness and corrosion resistance of Cr-B coatings produced on Vanadis 6 tool steel. In this study, chromium and boron were added to the steel surface using a laser alloying process. The main purpose of the study was to determine the impact of those chemical elements on surface properties. Chromium and boron as well as their mixtures were prepared in various proportions and then were applied on steel substrate in the form of precoat of 100 µm thickness. Depending on the type of precoat used and laser processing parameters, changes in microstructure and properties were observed. Coatings produced using precoat containing chromium and boron mixture were characterized by high microhardness (900 HV0.05–1300 HV0.005) while maintaining good corrosion resistance. It was also found that too low laser beam power contributed to the formation of cracks and porosity.

scholarly journals Surface Modification of a Nickel-Free Austenitic Stainless Steel by Low-Temperature Nitriding

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1845
Author(s):  
Francesca Borgioli ◽  
Emanuele Galvanetto ◽  
Tiberio Bacci
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Stainless Steels ◽  
Volume Fraction ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Surface Layers ◽  
Modified Surface

Low-temperature nitriding allows to improve surface hardening of austenitic stainless steels, maintaining or even increasing their corrosion resistance. The treatment conditions to be used in order to avoid the precipitation of large amounts of nitrides are strictly related to alloy composition. When nickel is substituted by manganese as an austenite forming element, the production of nitride-free modified surface layers becomes a challenge, since manganese is a nitride forming element while nickel is not. In this study, the effects of nitriding conditions on the characteristics of the modified surface layers obtained on an austenitic stainless steel having a high manganese content and a negligible nickel one, a so-called nickel-free austenitic stainless steel, were investigated. Microstructure, phase composition, surface microhardness, and corrosion behavior in 5% NaCl were evaluated. The obtained results suggest that the precipitation of a large volume fraction of nitrides can be avoided using treatment temperatures lower than those usually employed for nickel-containing austenitic stainless steels. Nitriding at 360 and 380 °C for duration up to 5 h allows to produce modified surface layers, consisting mainly of the so-called expanded austenite or gN, which increase surface hardness in comparison with the untreated steel. Using selected conditions, corrosion resistance can also be significantly improved.

Factors Influencing the Rate-of-Pickling Test on Tin-Plate Steel★

CORROSION ◽  
1959 ◽  
Vol 15 (3) ◽  
pp. 51-56 ◽  
Author(s):  
R. M. HUDSON ◽  
G. L. STRAGAND
Keyword(s):  
Weight Loss ◽  
Corrosion Resistance ◽  
Steel Surface ◽  
Lag Time ◽  
Rate Of Change ◽  
Surface Layers ◽  
Experimental Conditions ◽  
Constant Rate ◽  
High Concentrations ◽  
Future Work

Abstract “Lag time” is a measure of the time of pickling necessary to produce a constant rate of weight loss from steel immersed in acid. This measurement has been used as a guide for improving the corrosion resistance of commercial electrolytic tin plate. It is determined by measuring either the rate of change of weight loss, hydrogen evolution, or corroding potential of a specimen in 6N hydrochloric acid at 90 C (194 F.) The lag time depends on surface effects inasmuch as removing the surface layers of steel by abrasion or by pickling destroys the lag. The influence of box-annealing atmospheres, cleanliness of steel, and time-temperature cycles on lag time have been investigated, and the complexity of these effects has been demonstrated. Explanations in terms of oxidation or decarburization of the steel surface during annealing are not feasible for the development of lag time under all the experimental conditions studied. Preliminary data demonstrating the high concentrations of certain elements on the steel surface before annealing, and the enrichment of the surface layer by some of these elements during annealing, are suggested as particularly promising areas for future work. In this way lag time phenomena in tin-plate steels may be better understood and further improvement in tin-plate corrosion resistance can be made. 2.3.4

Effects of Laser Processing Parameters on Grain Boundary Character Distribution and Corrosion Resistance of Austenite Stainless Steel

2007 ◽  
Vol 561-565 ◽  
pp. 2473-2476 ◽  
Author(s):  
Sen Yang ◽  
Hiroyuki Kokawa ◽  
Zhan Jie Wang
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Laser Processing ◽  
Processing Parameters ◽  
Laser Surface ◽  
304 Stainless Steel ◽  
Grain Boundary Character Distribution ◽  
Grain Boundary Character ◽  
Laser Surface Remelting ◽  
Character Distribution

In order to modify grain boundary character distribution (GBCD) and to improve intergranualr corrosion (IGC) resistance of 304 stainless steel, laser surface remelting experiments were conducted on 304 stainless steel using a 2kW CW Nd: YAG laser, and the effects of laser processing parameters on GBCD and corrosion resistance were investigated in detail under the optimal annealing condition (1220K 28h). The experimental results showed that combination of laser surface remelting and the following annealing treatment could change the GBCD remarkably and improve the IGC resistance of 304 stainless steel. However, there are no obvious effects of laser processing parameters on the final depth of the processed zone, although the depth of the molten pool increases with the increase of the laser output power or the decrease of the scanning velocity, and the subsequent GBCD and corrosion resistance.

Application of Laser Remelting Treatments to Improve the Properties of Ti6Al4V Alloy

2012 ◽  
Vol 713 ◽  
pp. 25-30 ◽  
Author(s):  
M.R. Amaya-Vázquez ◽  
J.M. Sánchez-Amaya ◽  
Z. Boukha ◽  
K. El Amrani ◽  
Francisco Javier Botana
Keyword(s):  
Corrosion Resistance ◽  
High Power ◽  
Laser Processing ◽  
Shielding Gas ◽  
Laser Remelting ◽  
Medium Energy ◽  
Present Contribution ◽  
First Time ◽  
Power Diode ◽  
High Power Diode Laser

Ti6Al4V is the α-β alloy most employed in industry. The modification of its properties can be achieved with conventional heat treatments and/or with laser processing. Laser remelting (LR) has been applied to Ti6Al4V by other authors with excimer and Nd-YAG laser, employing pure argon as shielding gas to prevent risk of oxidation. In the present contribution, LR has been applied for the first time with a high power diode laser shielded with argon to improve the properties of Ti6Al4V. Results showed that remelted samples (with medium energy densities) have higher microhardness and better corrosion resistance than Ti6Al4V base metal.

PRACTICAL USE OF THE SURFACE LAYERS OF LASER MODIFIED WC-Cu COATINGS

Tribologia ◽  
2016 ◽  
Vol 270 (6) ◽  
pp. 121-130
Author(s):  
Izabela PLISZKA ◽  
Norbert RADEK ◽  
Aneta GĄDEK-MOSZCZAK ◽  
Peter FABIAN
Keyword(s):  
Carbon Steel ◽  
Laser Treatment ◽  
Laser Processing ◽  
Resistance Test ◽  
Test Results ◽  
Mechanical Seals ◽  
Surface Layers ◽  
Friction Resistance ◽  
Before And After ◽  
Wear Coatings

The article presents the study of the effect of laser treatment on the microhardness of WC-Cu coatings applied by electro spark deposition. Observations of friction resistance test results allowed the evaluation of the coatings after laser treatment. The studies were conducted using WC-Cu electrodes, produced by sintering of nanostructural powders. The anti-wear coatings were electro-spark deposited over C45 carbon steel by means of EIL-8A, while the laser processing was performed by electro coats applied using a Nd:YAG, BLS720. Model tests were carried on test mechanical seals for rings made of SiC and WC-Cu coatings before and after laser treatment.

scholarly journals Production and Properties of FeB-Fe2B-Fe3(B,C) Surface Layers Formed on Tool Steel Using Combination of Diffusion and Laser Processing

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1130 ◽  
Author(s):  
Aneta Bartkowska
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Laser Beam ◽  
Tool Steel ◽  
Laser Processing ◽  
Steel Substrate ◽  
Beam Power ◽  
Slight Reduction ◽  
Laser Beam Power ◽  
Study Results

The paper presents the study results of laser remelting diffusion boronized layers produced on CT90 tool steel. A diffusion boronized layer was produced at 950 °C in a powder mixture containing boron carbide as a source of boron. A needle-like microstructure of iron boride was obtained. After diffusion boronizing, the specimens were subjected to laser processing, which was carried out using a diode laser with a nominal power of 3 kW. Three laser beam power values were applied (600, 900, and 1200 W). The aim of the study was to investigate the microstructure, microhardness, chemical, and phase composition as well as the wear and corrosion resistance of newly formed FeB-Fe2B-Fe3(B,C) layers. As a result of the laser beam interaction, the needle-like borides occurring in the subsurface zone were remelted, and three characteristic areas were obtained: the remelted zone, the heat-affected zone, and the substrate. The properties of newly formed layers have improved in comparison to diffusion boronized layers (except for corrosion resistance). It should be noted that using the highest laser beam power contributed to a slight reduction in wear resistance. Both the reduced corrosion and wear resistance were caused by greater remelting of the steel substrate and thus by the increased iron content in the formed layer.

Study on Behavior of Ni-Based and Fe-Based Hardfacing Alloys in Plant Valves with Laser Cladding

2011 ◽  
Vol 287-290 ◽  
pp. 2267-2270
Author(s):  
Ai Qin Xu ◽  
Ge Yan Fu ◽  
Chen Wang ◽  
Hui Zhang ◽  
Shuang Liu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Laser Cladding ◽  
Laser Processing ◽  
Processing Parameters ◽  
Dense Microstructure ◽  
Wear And Corrosion ◽  
Wear And Corrosion Resistance

Two new kinds of Ni-based and Fe-based alloy power have been developed. Both kinds of power have been successfully coated by laser cladding on the surface of stainless steel as strengthening layers. The morphology and microstructure of these coatings have been analyzed by SEM and XRD, the mircohardness, wear and corrosion resistance of Ni-based and Fe-based laser cladding coatings have been measured respectively. The analysis reveals that both coatings with smooth and successive surfaces and homogeneous morphology have been obtained under the proper laser processing parameters; besides, Ni-based and Fe-based coatings have fine, well-proportioned and dense microstructure, and better joints with the substrates, respectively. So the results indicate that Ni-based and Fe-based alloys can supersede the cobalt-based alloys in the certain conditions.

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