Process Design of Strengthening and Toughening Treatment for 65Mn Steel by Powder RE-Boronizing Method under Low Temperature

2014 ◽  
Vol 941-944 ◽  
pp. 1414-1419
Author(s):  
Xiao Ming Yuan ◽  
Hong Yu Wang ◽  
Yu Feng Zhao ◽  
Xiao Jing Xu ◽  
Man Cheng
Keyword(s):  
Particle Size ◽  
Wear Resistance ◽  
Low Temperature ◽  
Process Design ◽  
Orthogonal Test ◽  
Basic Component ◽  
Surface Wear ◽  
Medium Temperature ◽  
Tempering Treatment ◽  
Shock Resistance

In order to improve the surface wear-resistance and overall shock-resistance of 65Mn steel, effects of rare earth (RE) particle size, adding amount and boronizing time subjected to quenching and medium-temperature tempering treatment were studied systematically. Optimizing basic component of low-temperature boronizing reagent and RE types, the depth of boronizing layer was selected as main evaluation parameter through the orthogonal test of RE-boronizing. Experimental results show that, cerium oxide with particle size of 20nm and content of 4% has the best effect of accelerating boronizing process on 65Mn steel at 700°C for 9 h, and the depth of boronizing layer with RE-boronizing is about 3.3 times than without adding RE; meanwhile, the heart of 65Mn steel still keeps good strength and toughness due to temper troostite microstructure. It can be concluded that the strengthening and toughening treatment of low-temperature RE-boronizing can obtain hard-surface and tough-core properties on 65Mn steel.

Research on Boronizing of the Whetstone Forming Die

2011 ◽  
Vol 704-705 ◽  
pp. 261-265
Author(s):  
Jing Chen ◽  
Shao Xiang Hao ◽  
Xun Fan
Keyword(s):  
Wear Resistance ◽  
Rare Earth ◽  
Orthogonal Test ◽  
Line Scan ◽  
Optimum Parameters ◽  
Maximum Value ◽  
Two Samples ◽  
Tempering Treatment ◽  
Temperature Time ◽  
Quenching And Tempering

The main failure forms of whetstones forming die is serious wear on the work face, and the boronizing technology can be used to improve the hardness and wear resistance on the work face of the whetstones forming die. In this paper, the orthogonal test was used to obtain the optimum parameters of temperature, time and the amount of addition of rare earth in the boronizing process of die. The line scan spectrum shows that there are some of elements such as B, C, Al, Cr, Si and Fe etc in boronizing layer, and their content are changed during boronizing. The microhardness of boronization layer was measured, and the result showed that maximum value of microhardness of boronizing layer appears in subsurface, not in surface, and lowers along depth of boronizing layer. By comparing different wear curve of abrasive samples with different treated, we can see that the highest wear resistance of surface is in the sample with the optimization of boronization treatment +970°C quenching and 200°C tempering; followed by quenching and tempering treatment; the lowest wear resistance of the surface is the sample without the boronizing treatment, and the rest sample are between these two samples. After optimization of boronization treatment +quenching and tempering, the lifetime of the whetstones forming die with boronizing is 3.5 times than the old one. Keywords: Boronizing; Whetstone; Forming Die

SIMOCH

Alloy Digest ◽  
1966 ◽  
Vol 15 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Impact Strength ◽  
Cold Work ◽  
Heat Treating ◽  
High Impact ◽  
High Shock ◽  
Alloy Tool ◽  
High Impact Strength ◽  
Shock Resistance

Abstract SIMOCH is a low alloy tool steel having high shock resistance, high impact strength and excellent wear resistance. It is recommended for many hot work and cold work applications. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-186. Producer or source: Teledyne Vasco.

scholarly journals Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Urban Areas ◽  
Waste Heat ◽  
Local Heating ◽  
District Heating ◽  
Heat Pumps ◽  
Hot Water ◽  
Local Network ◽  
Medium Temperature

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

Phase transformation and Raman spectra in BaTiO3 nanocrystals

2002 ◽  
Vol 718 ◽  
Author(s):  
Jian Yu ◽  
X. J. Meng ◽  
J.L. Sun ◽  
G.S. Wang ◽  
J.H. Chu
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Low Temperature ◽  
Long Range ◽  
Lattice Expansion ◽  
Inversion Symmetry ◽  
Range Interaction ◽  
Cooperative Phenomena ◽  
Long Range Interaction ◽  
Hydrothermal Methods

AbstractIn this paper, size-induced ferroelectricit yweakening, phase transformation, and anomalous lattice expansion are observed in nanocrystalline BaTiO3 (nc-BaTiO3) deriv ed b y low temperature hydrothermal methods, and they are w ellunderstood using the terms of the long-range interaction and its cooperative phenomena altered by particle size in covalen t ionic nanocrystals. In cubic nc-BaTiO3, five modes centerd at 186, 254, 308, 512 and 716 cm-1 are observed Raman active in cubic nanophase, and they are attributed to local rhombohedral distortion breaking inversion-symmetry in cubic nanophase. The254 and 308 cm-1 modes are significantly affected not only by the concentration of hydroxyl defects, but also their particular configuration. And the 806 cm-1 modes found to be closely associated with OH - absorbed on grain boundaries.

scholarly journals Low temperature synthesis and characterization of Mn3O4 nanoparticles

2007 ◽  
Vol 5 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Abdülhadi Baykal ◽  
Yüksel Köseoğlu ◽  
Mehmet Şenel
Keyword(s):  
Particle Size ◽  
Infrared Spectroscopy ◽  
Low Temperature ◽  
Synthesis And Characterization ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
X Ray ◽  
Peak Broadening ◽  
Mn3o4 Nanoparticles

AbstractHeating hydrous manganese (II) hydroxide gel at 85 °C for 12 hours produces Mn3O4 nanoparticles. They were characterized by X-ray powder diffraction (XRD) and infrared spectroscopy (FTIR). The particle size estimated from the SEM and X-ray peak broadening is approximately 32 nm, showing them to be nanocrystalline. EPR measurements confirm a typical Mn2+signal with a highly resolved hyperfine structure.

An Experimental Investigation on Mechanical and Wear Properties of Al7075/SiCp Composites: Effect of SiC Content and Particle Size

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Thella Babu Rao
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Ultimate Tensile Strength ◽  
Matrix Material ◽  
Mechanical Tests ◽  
Experimental Investigations ◽  
Wear Properties ◽  
Sic Particles ◽  
Sic Particle

One of the major advantages of metal matrix composites (MMCs) is that their tailorable properties meet the specific requirements of a particular application. This paper deals with the experimental investigations done on the effects of the reinforcement particulate size and content on the Al7075/SiC composite. The composites were manufactured using stir casting technique. The effect of SiC particle size (25, 50, and 75 μm) and particulate content (5, 10, and 15 wt %) on the microstructural, mechanical properties, and wear rate of the composites was studied and the results were analyzed for varied conditions of reinforcement. Scanning electron microscope (SEM) examinations were used to assess the dispersion of SiC particles reinforced into the matrix alloy and was found with reasonably uniform with minimal particle agglomerations and with good interfacial bonding between the particles and matrix material. X-ray diffraction (XRD) analysis confirmed the presence of Al and SiC with the composite. The results of mechanical tests showed that the increasing SiC particle size and content considerably enhanced the ultimate tensile strength and hardness of the composites while the ductility at this condition was decreased. The highest ultimate tensile strength of 310 MPa and hardness of 126 BHN were observed for the composites containing 15 wt %. SiC at 75 μm. Lesser the wear resistance of the reference alloy while it was enhanced up to 40% with the composites. The wear resistance was increased up to 1200 m of sliding distance for all the composites, whereas for the composite containing 75 μm SiC particles, it was extended up to 1800 m.

scholarly journals Optimization of proppant parameters for CBM extraction using hydrofracturing by orthogonal experimental process

2020 ◽  
Vol 17 (3) ◽  
pp. 493-505 ◽  
Author(s):  
Haoze Li ◽  
Bingxiang Huang ◽  
Qingying Cheng ◽  
Xinglong Zhao
Keyword(s):  
Particle Size ◽  
Orthogonal Test ◽  
Coal Mass ◽  
Tensile Fracture ◽  
Experimental Conditions ◽  
Embedded Value ◽  
Fracture Area ◽  
Creep Time ◽  
Experimental Process ◽  
The Impact

Abstract Proppant placement concentration, particle size and creep time are important factors that affect the embedment of proppant into coal. Based on multistage creep, an orthogonal test is conducted, and an optimal proppant scheme for different closure stresses obtained. The results show that with increased proppant placement concentration, the number of coal fractures increases and the elastic modulus of the fracture area decreases. As the proppant particle size decreases, the plasticity of fracture-proppant assemblies increases gradually. The yield limit is highest when the particle size is 20/40 mesh. During the proppant embedding process, localization or uneven distribution of proppant results in tensile stress parallel to the fracture surface, which induces tensile fracture in the coal. In the fracture-proppant assembly areas, proppant fractures are severe and yield lines appear. As proppant concentration increases, more energy is accumulated during the proppant compaction stage, resulting in energy release producing craters and crevasses. The energy released also causes increased stress in the proppant-coal contact area and fracturing to the coal mass. The longer the creep time, the weaker the impact and the smaller is fluctuation. Moreover, we find that the orthogonal test can effectively analyze the importance of each parameter. Proppant placement concentration was found to have the highest influence on the process of proppant embedding into coal, followed by particle size and then time. Under experimental conditions, the lowest proppant-embedded value in coal samples was observed with proppant placement concentration of 2 kg m−2 and particle size of 20/40 mesh.

Wear resistance of structural steels after low-temperature cyaniding and carbonitriding

1975 ◽  
Vol 17 (11) ◽  
pp. 986-988
Author(s):  
Yu. M. Lakhtin ◽  
G. N. Neustroev ◽  
N. A. Airapetyan
Keyword(s):  
Wear Resistance ◽  
Low Temperature ◽  
Structural Steels

scholarly journals LOW-TEMPERATURE SYNTHESIS OF SUPERPARAMAGNETIC Zn0.8Ni0.2Fe2O4 FERRITE NANOPARTICLES

2018 ◽  
Vol 56 (1) ◽  
pp. 31
Author(s):  
Luong Thi Quynh Anh ◽  
Nguyen Van Dan ◽  
Do Minh Nghiep
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Oleic Acid ◽  
Low Temperature ◽  
Coercive Force ◽  
Saturation Magnetization ◽  
Ferrite Nanoparticles ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Co Precipitation

The crystalline nanoparticles of Ni0.2Zn0.8Fe2O4 ferrite were synthesized by chemical co-precipitation with precursor concentration of 0.1M, then modified by 0.25M solution of oleic acid in pentanol, finally heated at temperatures 120, 140, 160 and 180oC for 6h in autoclave. The XRD, EDS and TEM confirmed that all of samples are crystalline and their particle size are 6, 6.5, 7 and 8 nm. The magnetic properties showed that the coercive force, the remanence of samples are about zero, the saturation magnetization Ms has values from 14.20 to 27.12 emu/g.

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