Surface Layers Produced by Modified Floe Ferritic Nitrocarburising

2015 ◽  
Vol 812 ◽  
pp. 253-258
Author(s):  
Andrea Szilagyine Biro ◽  
Endre Szabo ◽  
Miklos Tisza
Keyword(s):  
Wear Resistance ◽  
White Layer ◽  
Nitrided Layer ◽  
High Surface ◽  
Surface Hardness ◽  
Structural Steels ◽  
Surface Alloying ◽  
Tool Steels ◽  
Micro Hardness ◽  
Surface Layers

Ferritic nitrocarburising is a surface alloying heat treatment, which can provide to components high surface hardness, thus improved wear resistance. In structural steels the porosity of white layer has a key role in wear resistance: the porosity is undesirable. For tool steels the absence of white layer is undesirable. Floe process is one way to decrease the porosity of white layer. During our experiments we applied a modified Floe process on two different steels. The acontol of this process is simpler than conventional process. We measured the micro-hardness as a function of depth from the surface, and we made microscopic examination to analyse the structure of nitrided layer.

Surface Hardness Modify and Improve Wear Properties of EP\ NanoZrO2

2021 ◽  
Vol 19 (2) ◽  
pp. 77-82
Author(s):  
Fadhil K. Farhan ◽  
Aws Abbas Hussein ◽  
Ali Q. Tuama
Keyword(s):  
Wear Resistance ◽  
High Surface ◽  
Ceramic Powder ◽  
High Surface Area ◽  
Surface Hardness ◽  
Weight Ratio ◽  
Hardness Test ◽  
Wear Properties ◽  
Mechanical Mixing ◽  
Dioxide Powder

The liquid and mechanical mixing method was used in addition to ultrasound technology to prepare samples according to standard conditions. The percentage of cementing with ceramic powder was adopted from 1% to 4% as a weight ratio, and by using mixing drivers, nanocomposites were prepared depending on the theoretical density of the components. The velvet density was measured using Archimedes' method, and the results showed a successive improvement and increase in density with the weight ratio of addition. The results of the particulate hardness test showed a significant improvement in the results of the prepared nanostructures compared to the base sample (pure epoxy). With regard to the properties of wear resistance (wear modulus) using the screw-on-disk method, the cemented samples showed a higher wear resistance compared to the base sample. The results were interpreted based on the values of density and hardness in addition to the properties possessed by the ceramic powder of high surface area and average granular size of 32 nanometers through scanning electron microscopy. In this work, nanostructures based on (a polymer) supported with nanoscale zirconium dioxide powder were developed.

UHB RIGOR A2

Alloy Digest ◽  
1977 ◽  
Vol 26 (3) ◽  
Keyword(s):  
Wear Resistance ◽  
Compressive Strength ◽  
High Surface ◽  
Surface Hardness ◽  
Heat Treating ◽  
High Dimensional ◽  
Metal Working ◽  
Good Resistance ◽  
High Hardenability ◽  
Compression Resistance

Abstract UHB RIGOR AR is a chromium-molybdenum-vanadium tool steel characterized by high surface hardness, high hardenability, high dimensional stability after hardening and tempering, high compression resistance, good machinability, good resistance to tempering and good wear resistance. Its many uses include metal-working tools, dies for porcelain and gages. This datasheet provides information on composition, physical properties, hardness, elasticity, and compressive strength. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-315. Producer or source: Uddeholm Aktiebolag.

The Influence of Plasma Nitriding Period on Nitrided Layers Thickness

2016 ◽  
Vol 258 ◽  
pp. 395-398 ◽  
Author(s):  
Ondrej Pilch ◽  
Vojtěch Hruby
Keyword(s):  
Optical Microscopy ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Surface Hardness ◽  
Experimental Methods ◽  
Nitriding Process ◽  
Material Surface ◽  
Hardness Testing ◽  
Surface Layers ◽  
Cross Sectional

The plasma nitriding as a technology for finishing of material surface layers was carried out on selected material. The effect of plasma nitriding conditions on the thickness and hardness of nitrided layer was investigated. The influence of plasma nitriding period on the thickness of the plasma nitrided layers was comprehensively assessed on the C55 steels. Plasma nitriding was carried out on selected material at 500 °C under 280 Pa with a mixture atmosphere of H2 and N2 in the plasma nitriding equipment. The period of the plasma nitriding process was changeable from 5 to 20 hours. Measurements of the properties of nitrided layers of selected material were solved by using experimental methods in accordance with standards. The samples were characterized by GDOES spectrometry, optical microscopy, and hardness testing. The depths of the plasma nitriding layers were also detected using cross-sectional microhardness profiles. Relation between plasma nitriding period and a thickness of a nitrided layer was explained and has shown that microhardness and surface hardness of mentioned samples were significantly increased.

Evaluation of Thermal Fatigue Properties of Surface Treated AISI H13 Steel for Aluminum Die-Casting

2006 ◽  
Vol 326-328 ◽  
pp. 1173-1176
Author(s):  
Kuk Tae Youn ◽  
Young Mok Rhyim ◽  
Won Jon Yang ◽  
Jong Hoon Lee ◽  
Chan Gyu Lee
Keyword(s):  
Crack Initiation ◽  
Diffusion Layer ◽  
Thermal Fatigue ◽  
White Layer ◽  
High Surface ◽  
Surface Hardness ◽  
Fatigue Properties ◽  
H13 Steel ◽  
Heat Treated ◽  
Very High

The influence of surface treatment such as nitriding, TNHT(Ti Nano Heat-treatment, PHILOS TECHNOLOGIES, INC.) and PVD coating on the thermal crack propagation behavior of hot work die steel was investigated. To examine the thermal fatigue resistance, the cyclic thermal shock system consisted of induction heating and water spray quenching unit was constructed and Lm is proposed as the index representing the susceptibility to crack initiation and propagation. Thermal stress depending on test temperature was also simulated by FEM. The TNHT specimen showed lower Lm value than as-heat treated specimen but, in the case of maximum and average crack length, the TNHT specimen exhibited higher value than those of as-heat treated specimen. This means that the small number of large cracks were initiated and propagated selectively in the TNHT specimen. This result can be caused by two contrary effects of diffusion layer, those are introduction of the residual compressive stress good for mitigation of thermal tensile stress and very high surface hardness harmful for crack initiation. However, Lm value of salt-bath nitriding specimen was very high due to the white layer in spite of the existence of diffusion layer.

Ammonia dilution during nitriding and carbonitridingin a fluidized bed of 41CrAlMo7 constructional steel

2019 ◽  
Vol 24 (3) ◽  
pp. 34-41
Author(s):  
Tadeusz Żółciak ◽  
Zbigniew Łataś
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Aluminum Oxide ◽  
Fluidized Bed ◽  
Constant Temperature ◽  
Nitrided Layer ◽  
High Surface ◽  
Surface Hardness ◽  
Constructional Steel ◽  
Pure Nitrogen

Nitriding of 41CrAlMo7 steel was carried out in a fluidized bed of aluminum oxide at a constant temperature of 570oC/4h in ammonia with technical nitrogen or with nitrogen-hydrogen mixture. Carbonitriding was carried out in ammonia with technical nitrogen for two different carbon carriers. In addition, one process was carried out in ammonia with the addition of 5% propane. The influence of diluting ammonia with pure and technical nitrogen upon the hardness and thickness of the nitrided layer was investigated. The hardness and thickness of the carbonitrided layer in ammonia with technical nitrogen and natural gas or carbon dioxide were compared with the parameters of the layer carbonitrided in ammonia and propan. High surface hardness and thickness of the nitrided layer were obtained with the participation of 70% of pure nitrogen or 30% of technical nitrogen in a mixture with ammonia after preliminary oxidation at 350oC/ 30min in air. In case of carbonitriding, the highest hardness and thickness of the nitrided layer were obtained in a mixture of ammonia with and the addition of 5% propane, and the highest thickness of the nitride compound zone in a mixture of ammonia and technical nitrogen with the addition of natural gas or carbon dioxide.

Study of High Co Superhard High Speed Steel Surface

2009 ◽  
Vol 610-613 ◽  
pp. 253-256
Author(s):  
Zhong Hou Li ◽  
Sha Sha Liu ◽  
Zhi Yong Cheng
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Steel Surface ◽  
High Surface ◽  
Surface Hardness ◽  
High Speed Steel ◽  
Low Alloy Steel ◽  
Surface Alloying ◽  
Plasma Surface ◽  
Plasma Surface Alloying

Cobalt- superhard high speed steel layer has been formed on the surface of low alloy steel 20Cr2V by tungsten-molybdenum-cobalt plasma surface alloying and following plasma carbonizing. After plasma surface alloying, a homogeneous and dense surface alloying layer was formed, thickness of which is 200μm. Composition, microstructure and properties of the alloying layer were investigated. Contents of W, Mo, Co, Cr, V and C in the surface layer reach 8%,5%, 6% ,4%,1.5% and 1.5% or so respectively. The concentrations of alloy elements basically meet the requirements of high cobalt type superhard high speed steel. Constituent phases of the surface layer were martensite, M7C3 ,M2C and Cr3C2 carbides and μ phase after quenching treatment. The advanced gradient superhard high speed steel possesses not only high surface hardness, high anti-temper softening ability but also enough toughness.

Structure and Phase Composition of a Ti Film–Al Substrate System Irradiated with an Intense Pulsed Electron Beam

2018 ◽  
Vol 781 ◽  
pp. 101-107
Author(s):  
Yurii Ivanov ◽  
Olga V. Krysina ◽  
Pavel Moskvin ◽  
Elizaveta A. Petrikova ◽  
Olga V. Ivanova ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Electron Beam ◽  
High Surface ◽  
Pure Titanium ◽  
Surface Hardness ◽  
Vacuum Arc ◽  
High Wear Resistance ◽  
Commercially Pure Titanium ◽  
Plasma Cathode ◽  
Commercially Pure

Commercially pure A7 aluminum was exposed to surface modification in a single vacuum cycle which included vacuum arc evaporation and deposition of commercially pure titanium and intense electron beam irradiation and melting of the film–substrate system using a plasma-cathode pulsed electron source. The deposited Ti film thickness was 0.5 and 1 μm. The irradiated Ti–Al system revealed a multilayer multiphase structure consisting of submicro-and nanosized elements with intermetallic inclusions Al3Ti, Al2Ti, and TiAl3. The Ti film during irradiation broke up into fragments with their immersion in the molten Al surface layer to a depth of 20 μm. The modified material surpassed the initial aluminum in wear resistance by a factor of 2.4 and in microhardness by a factor larger than 4. The main cause for the high surface hardness and high wear resistance of the modified aluminum was likely the formation of both the intermetallic particles and the Ti-hardened transition layer.

Characterization on Duplex Treated Coating Fabricated by Laser Cladding and Active Screen Plasma Nitriding

2011 ◽  
Vol 69 ◽  
pp. 93-98
Author(s):  
Xiao Dong Zhang ◽  
Bin Shi Xu ◽  
Shi Yun Dong ◽  
Zhi Jian Wang ◽  
Han Shan Dong ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Plasma Nitriding ◽  
White Layer ◽  
Surface Hardness ◽  
Nitrogen Diffusion ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Hardness Tester ◽  
Active Screen Plasma Nitriding ◽  
Active Screen

In order to enhance the performances of laser remanufacturing part, we combined laser cladding with active screen plasma nitriding duplex treatment to repair metal part. The microstructure, phase structure and micro-hardness of duplex treated coating were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and micro-hardness tester. Wear tests were carried out on reciprocating wear tester under dry sliding condition. The results show that the white layer and the nitrogen diffusion layer were formed after nitriding treatment. The duplex treated coating consists mainly of γ-Fe, CrN, Fe4N and Fe3N. The duplex treated coating improved not only surface hardness but also wear resistance.

scholarly journals The resistance of ledeburitic tool steels against the abrasive wear

2012 ◽  
Vol 60 (6) ◽  
pp. 231-242 ◽  
Author(s):  
Jaromír Liška ◽  
Josef Filípek
Keyword(s):  
Wear Resistance ◽  
Laboratory Test ◽  
Abrasive Wear ◽  
Structural Steel ◽  
Aluminium Alloys ◽  
Structural Steels ◽  
Tool Steels ◽  
Maximum Hardness ◽  
Resistant Material ◽  
Operational Tests

The ledeburitic tool steels which used to be used mainly for cutting and shaping tools nowadays are frequently used for a manufacture of injection moulds, moulds for pressure castings of aluminium alloys and for moulds for ceramics processing. The article deals with findings of ledeburitic tool steels resistance against abrasive wear. For the tests there were prepared the test samples of ledeburitic tool steels 19 436 and 19 573 (both according to ČSN). Moreover there were prepared the samples from structural abrasion resistant material Hardox 450 and from unalloyed structural steel 11 373 (according to ČSN). A wear resistance was examined by means of a laboratory test with an abrasive cloth and the Bond’s device. Hereafter the article deals with a possibility of utilisation of ledeburitic alloyed steels for a manufacture of tools for a land processing. For the examination of a resistance against wear in land there was made a plough test in which the tested samples were mounted on plough blades. By means of both the laboratory and operational tests there was found multiple higher resistance against wear of ledeburitic tool steels rather than of structural steels. During a land processing there was found unsuitability of steels processed for a maximum hardness, which came out as fractures of several samples.

Multiple Needle Cathodes Plasma Surface Alloying of Ti6Al4V with W-Mo-C-N

2008 ◽  
Vol 373-374 ◽  
pp. 426-429
Author(s):  
Yue Fei Zhang ◽  
Xin Chao Bian ◽  
Qiang Chen ◽  
Guang Qiu Zhang ◽  
Yuan Gao
Keyword(s):  
Wear Resistance ◽  
Layer Structure ◽  
Surface Hardness ◽  
High Hardness ◽  
Surface Alloying ◽  
Cathode Plasma ◽  
Working Pressure ◽  
Plasma Surface ◽  
Pure Graphite ◽  
Plasma Surface Alloying

A multiple-needle-cathode plasma surface alloying process has been developed for improving the properties of surface hardness, wear resistance and corrosion resistance of Ti6Al4V. The process is carried out at temperatures below 800 °C and facilitates the simultaneous introduction of W, Mo,nitrogen and carbon into the surfaces of Ti6Al4V forming gradient alloying layer structure with an extremely high hardness. The process is performed at working pressure of 30Pa-80Pa with 9-needle-cathode of W80Mo20 alloy rods array and a high pure graphite plate cathode as target electrode. A maximum microhardness is 4-6 times much harder than the substrate. The results show the presence of carbide and nitride ceramics phases contribute to high microhardness and wear resistance. The multiple-needle-cathode discharge plasma treatment is an effective method for improvement of the mechanical and tribological properties of titanium-base alloys by formation of graded diffusion hard surface layers. The present paper describes this novel process and properties characteristics.

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