Relationship between processing parameters, alloy atom diffusion distance and surface hardness in laser hardening of tool steel

2007 ◽  
Vol 189 (1-3) ◽  
pp. 435-440 ◽  
Author(s):  
Henrikki Pantsar
Keyword(s):  
Tool Steel ◽  
Surface Hardness ◽  
Processing Parameters ◽  
Laser Hardening ◽  
Diffusion Distance ◽  
Atom Diffusion ◽  
Alloy Atom

Laser Surface Modification of Tool Steel for Semi-Solid Steel Forming

2008 ◽  
Vol 141-143 ◽  
pp. 255-260 ◽  
Author(s):  
Dermot Brabazon ◽  
Sumsun Naher ◽  
Patrick Biggs
Keyword(s):  
Surface Modification ◽  
Tool Steel ◽  
Co2 Laser ◽  
Surface Hardness ◽  
Amorphous State ◽  
Processing Parameters ◽  
Hardness Profile ◽  
X Ray Diffraction ◽  
Thermal Barriers ◽  
Semi Solid

This paper presents an analysis of the effect of CO2 laser processing parameters on the surface modification and heat treatment of steels. The CO2 laser and sample movement process parameters are presented. The controlled operation of these in conjunction with each other is required to obtain better surface hardness and structure. H13 tool steel samples were rotated at high speeds to keep exposure times below 0.3s. Laser processed samples were analysed using EDX spectroscopy, optical microscopy, Vickers and Martens micro-hardness testing, and X-ray diffraction (XRD). Results show how the hardness profile through the surface is related to the laser treatment and resultant microstructures. Increased surface hardness was noted due to a complete microstructural transformation to an amorphous state in the glazed samples. The usefulness of such coatings on tool steels, in conjunction with other thermal barriers, for the forming of semi-solid steel alloys is presented.

Local Microstructure and Hardness Variation After Pulsed Laser Micromelting on S7 Tool Steel

2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Justin D. Morrow ◽  
Frank E. Pfefferkorn
Keyword(s):  
Tool Steel ◽  
Surface Hardness ◽  
Pulsed Laser ◽  
Processing Parameters ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting ◽  
Microstructure And Properties ◽  
Surface Polishing ◽  
Diffusion Controlled

Laser surface melting is being increasingly used as a method of surface polishing steels and other alloys, but understanding the effect of this process on the microstructure and properties is still incomplete. This work experimentally explores several basic questions about how the surface microstructure and properties of S7 tool steel change during a pulsed laser micromelting (PLμM) process. Evaluations of the microstructure and hardness suggest that diffusion-controlled processes such as melt homogenization and surface back-tempering are relevant during rapid microscale laser melting and that the laser parameters and process planning contribute to determining the final surface hardness. The results also suggest that some influence can be exerted over the final hardness obtained from laser surface melting by changing the processing parameters.

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.

Effect of Friction Stir Processing Parameters on the Properties of AA7075-T73/Al2O3 Surface Metal Matrix Composite

2020 ◽  
Vol 1002 ◽  
pp. 140-150
Author(s):  
Ali H. Al-Helli ◽  
Ahmed R. Alhamaoy ◽  
Ayad Murad Takhakh
Keyword(s):  
Friction Stir Processing ◽  
Particle Distribution ◽  
Surface Hardness ◽  
Base Material ◽  
Processing Parameters ◽  
Optical Microscope ◽  
Friction Stir ◽  
Surface Composite ◽  
Surface Metal ◽  
Number Of Passes

Friction Stir Processing (FSP) technology was wielded to output the Al7075/ Al2O3 surface composite. The effects parameters of processing method on particle distribution have been studied. The microstructure and mechanical characteristics of the samples were examined using the optical microscope, SEM and hardness examination. Acquired consequences, showed that Al2O3 particles were in a good interior distribution inside the basement. This technique produced excellent bonding between the surface composite and the base material. On other hand the surface hardness was increased about 25% as compared with the substrate. In addition, grain matrix refinement and enhanced particle distribution were obtained after each FSP pass. Also the dispersion of Al2O3 particles in the stirred area became more homogeneous and the average hardness improved by increasing the number of passes.

Influence of loading conditions on wear behaviour of H11 tool steel

2019 ◽  
Vol 16 (5) ◽  
pp. 614-624 ◽  
Author(s):  
Sam Joshy ◽  
Jayadevan K.R. ◽  
Ramesh A. ◽  
Mahipal D.
Keyword(s):  
Plastic Deformation ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Tool Steel ◽  
Frictional Force ◽  
Normal Load ◽  
Hot Forging ◽  
Surface Hardness ◽  
Wear Behaviour ◽  
Content Type

Purpose In hot forging, a significant amount of forging force is used for overcoming frictional force at the die-billet interface. The high frictional force along with thermomechanical stress lead to wear, plastic deformation, mechanical fatigue and cracks, which reduce the service life of hot forging dies. Of all these different types of issues, wear is the predominant mode of failure in hot forging dies. This paper aims to describe mechanisms of wear transition in different loads at near forging temperature, occurring during sliding of chromium-based H11 tool steel specimens. Design/methodology/approach High temperature pin-on-disc tests are performed with pin specimens machined from bars of X38CrMoV5 steel, heat treated to surface hardness of 40-42 HRc. The disc is made of EN 31 steel with hardness of 60-62 HRc. Tests are performed at constant temperature of 500°C, and the normal load was varied from 20 to 70 N. Findings Scanning electron microscopy investigations on worn surface have revealed that wear is primarily due to abrasion and plastic deformation. The test results show an increasing trend in wear rate with increase in load up to 30 N, followed by a reversal in trend until 50 N. This transition in wear rate is caused by development of wear resistant layers, which are formed by compaction of wear debris particles on to the worn surfaces. These compact layers are found to be stable during load range from 40 and 50 N. However, with further increase in load, abrasive wear tracks are observed without any evidence of protective layers. As a result, there is an increase in wear rate with increase in loads above 50 N. In addition, plastic shearing was dominant over abrasive wear at this load regime. Originality/value The study on wear behaviour of H11 hot forging steel at 20 to 70 N will be an input to the research in hot forming industries.

Optimisation of Plasma Nitrocarburising for Reducing Wear in Dry Sliding Contacts

2016 ◽  
Vol 721 ◽  
pp. 389-393 ◽  
Author(s):  
Igor Velkavrh ◽  
Florian Ausserer ◽  
Stefan Klien ◽  
Joel Voyer ◽  
Alexander Diem ◽  
...  
Keyword(s):  
Surface Topography ◽  
Layer Thickness ◽  
Tool Steel ◽  
Compound Layer ◽  
Processing Parameters ◽  
Dry Sliding ◽  
Tribological Behaviour ◽  
Micromechanical Properties ◽  
Wear And Friction ◽  
Steel Substrates

In this study, tool steel substrates were plasma-nitrocarburised at different processing parameters and afterwards tribologically tested under non-lubricated sliding conditions. It was observed that the micromechanical properties of the compound layer (thickness, hardness, roughness, surface topography) strongly affect the tribological behaviour of the nitrocarburised surface and can be tailored through the adjustment of the nitrocarburising parameters so that very favourable wear and friction behaviours can be achieved.

Die Soldering Phenomenon on the H13 Tool Steel with Shot Peening and Nitriding Surface Treatment

2015 ◽  
Vol 1101 ◽  
pp. 157-163
Author(s):  
Myrna Ariati ◽  
Dwi Marta Nurjaya ◽  
Rizki Aldila
Keyword(s):  
Surface Treatment ◽  
Tool Steel ◽  
Shot Peening ◽  
Surface Hardness ◽  
Nitride Layer ◽  
H13 Steel ◽  
Gas Nitriding ◽  
Aisi H13 Steel ◽  
H13 Tool Steel ◽  
Aisi H13

Die soldering occurs when molten aluminum sticks to the surface of a die material and remains there after the ejection of the part. This resulted in low productivity and economic value in the foundry industry. Nitriding surface treatment is considered as an effective way in enhancing the service life of AISI H13 steel dies and to prevent soldering effect. The focus of this paper is to investigate the influence of three different surface conditions in terms of roughness, gas nitriding and pretreatment prior to gas nitriding on the soldering effect. Three kind of samples made of AISI H13 steel were pretreated (quenched and tempered) and followed by : shot peened, gas nitrided and shot peening followed by gas nitriding, were immersed in liquid melted ADC 12 Aluminium alloy at 30 seconds, 30 minutes, 2 hours and 5 hours, at a constant temperature of 680oC in a holding furnace. Characterizations on the surface of the steel were focused on the optical microstructure, microhardness profile, FE SEM observation and enegy dispersive spectrometry mapping. It was found that shot peening prior to nitriding gives a higher surface hardness and depth of nitride layer of H13 tool steel, 1140 HV (>70 HRC) and 120.5 μm, than the nitriding only process, 1033 HV (68 HRC) and 105 μm. The higher the hardness and depth of nitride layer expected would reduce the die soldering effect at the surface of the H13 tool steel dies. It was also found that the only shot peening treatment resulted in a tendency of soldering accompanied by the formation of intermetallic layers ; while soldering is not found on the nitrided and shot peened-nitrided samples.

Surface Treatment of AISI M2 Tool Steel by Laser Melting

2018 ◽  
Vol 786 ◽  
pp. 128-133 ◽  
Author(s):  
Mohamed Newishy ◽  
Hamed Abdel-Aleem ◽  
M.R. Elkousy ◽  
Iman El-Mahallawi ◽  
A. El-Batahgy
Keyword(s):  
Tool Steel ◽  
High Speed ◽  
Laser Scanning ◽  
Laser Energy ◽  
Surface Hardness ◽  
Laser Surface ◽  
Wear Properties ◽  
Scanning Velocity ◽  
Heating Source ◽  
Melted Zone

Attempt was made to improve the surface hardness and wear properties of AISI M2 high speed tool steel. Laser surface melting (LSM) of tool steel was conducted with 2.2 KW Nd:YAG laser as heating source. Conventional hardening of the tool steel was applied. Characterizing the LSM, with optical and field emission scanning electron microscopy and surface hardness technique was used to evaluate the micro-hardness and mechanical behaviour of different regions of melting pool. AISI M2 tool steel is approximately HV 260, hardness after conventional treatment was 850 HV and the hardness after laser surface heat treatment is around 900 HV. It was found that there is a considerable influence of the laser power density and scanning velocity on the melted zone dimensions and the re-solidified structure. Increasing laser energy and reducing the laser scanning rate results in deeper and wider melt pool formation.

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