The Impact of Grinding on Surface Integrity of Powder-Metallurgy High-Speed Steel (S390)

2013 ◽  
Vol 442 ◽  
pp. 52-57 ◽  
Author(s):  
Shan He Mu ◽  
Chuan Liang Cao ◽  
Xiang Lin Zhang ◽  
Zha Xiang ◽  
Xiu Mao
Keyword(s):  
Powder Metallurgy ◽  
Surface Integrity ◽  
High Speed ◽  
White Layer ◽  
Ground Surface ◽  
High Speed Steel ◽  
Residual Stress Field ◽  
Quality Design ◽  
The Impact ◽  
The Relationship

The paper presents an experimental study on the relationship betweenprocess parametersand surface integrity of powder-metallurgy high-speed steel S390 in ultraprecision grinding. The optimal machining parametershave been obtained based on the Taguchi quality design method.The affected layerinduced by ultraprecision grinding has a uniform white layerand an inconspicuous dark layer; there are some carbides in the white layer of some samples; a compressive residual stress field exists on the ground surface. In addition, experiments confirm that lapping can remove the white layer effectively and increase the compressive residual stresses with a growth rate of 65%.The derived results satisfy the real requirements in practice.

Effect of Spark Plasma Sintering on the Microstructure Evolution and Properties of M3:2 High-Speed Steel

2014 ◽  
Vol 788 ◽  
pp. 329-333
Author(s):  
Rui Zhou ◽  
Xiao Gang Diao ◽  
Jun Chen ◽  
Xiao Nan Du ◽  
Guo Ding Yuan ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Spark Plasma Sintering ◽  
High Speed ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Speed Steel ◽  
Continuous Heating ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Impact

Effects of sintering temperatures on the microstructure and mechanical performance of SPS M3:2 high speed steel prepared by spark plasma sintering was studied. High speed steel sintering curve of continuous heating from ambient temperature to 1200°C was estimated to analyze the sintering processes and sintering temperature range. The sintering temperature within this range was divided into groups to investigate hardness, relative density and microstructure of M3:2 high-speed steel. Strip and quadrate carbides were observed inside the equiaxed grains. SPS sintering temperature at 900°C can lead to nearly full densification with grain size smaller than 20μm. The hardness and bending strength are higher than that of the conventionally powder metallurgy fabricated ones sintered at 1270°C. However, fracture toughness of the high speed steel is lower than that of the conventional powder metallurgy steels. This can be attributed to the shape and distribution of M6C carbides which reduce the impact toughness of high speed steels.

Evolution of White Layer during Wire-Cutting and Comparison of Several Methods to Improve Surface Integrity for Fineblanking Tools

2018 ◽  
Vol 920 ◽  
pp. 141-148 ◽  
Author(s):  
Xiang Lin Zhang ◽  
Han Lin Peng ◽  
Li Yun Zhang ◽  
Chuan Liang Cao ◽  
Jing Wen Yi ◽  
...  
Keyword(s):  
Surface Integrity ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
White Layer ◽  
High Speed Steel ◽  
Tool Steels ◽  
Surface Residual Stress ◽  
Fine Blanking ◽  
Superior Mechanical Properties ◽  
Wire Cutting

Powder metallurgical high speed steel (such as S390) has superior mechanical properties and been used as fineblanking tools. The electrical discharge machining has been widely used for cutting fine blanking tools which are made of especially hard tool steels. Whereas, its thermal nature causes great concerns regarding surface integrity, which matters a lot to tool life. In the present study, the evolution of surface integrity of the S390 with multi-cutting is comprehensively compared. The result shows that the surface roughness, white layer thickness and surface residual stress decrease with the increase of cutting pass. Additionally, the effectiveness to remove white layer on HSS S390 by manual and towed polishing and electrolytic polishing are compared. At last, a device of abrasive water jet polishing is designated to remove the white layer resulted from wire-cutting.

Study of the Surface Integrity of Powder-Metallurgy High-Speed Steel (S390) Multi-Cut by Wire Electrical Discharge Machining

2013 ◽  
Vol 395-396 ◽  
pp. 1020-1025
Author(s):  
Xiang Zha ◽  
Chuan Liang Cao ◽  
Xiang Lin Zhang ◽  
Ji Jun Feng
Keyword(s):  
Residual Stress ◽  
Surface Integrity ◽  
Electrical Discharge ◽  
Retained Austenite ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
White Layer ◽  
Great Influence ◽  
High Speed Steel ◽  
Wire Electrical Discharge Machining

The surface integrity of powder metallurgical high speed steel (S390) cut by wire electrical discharge machining (WEDM) has a great influence on the its fatigue life. In this paper, a study focused on surface integrity including white layer, surface finish, retained austenite, carbide and residual stress changed with multi-cutting has been described. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrograph (EDS) analysis were performed in the examination of the evolution of surface integrity. The experimental results reveal that the surface roughness, micro-cracks, white layer thickness and surface residual stress decrease with the increase of cutting pass, but the amount of retained austenite in the resolidified layer of the surface after the second cutting pass is the highest, compared with the other cutting passes. The content of carbides increases with the cutting pass and few carbides appear in the top section of the white layer of the first two cutting passes.

VANADIS 23

Alloy Digest ◽  
1998 ◽  
Vol 47 (10) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Powder Metallurgy ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tool Steel ◽  
High Speed ◽  
High Speed Steel ◽  
Heat Treating

Abstract Vanadis 23 is a Cr-Mo-W-Va alloyed high-speed steel made by powder metallurgy. The tool steel offers an excellent combination of wear resistance and toughness. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on heat treating, machining, and surface treatment. Filing Code: TS-561. Producer or source: Uddeholm Corporation. See also Alloy Digest TS-552, March 1997.

Study on Edge Contact Area and Surface Integrity of Workpiece in Point Grinding Process

2009 ◽  
Vol 407-408 ◽  
pp. 577-581
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
High Speed ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Edge Contact ◽  
Cylindrical Grinding ◽  
Theoretic Foundations

During cylindrical grinding process, the geometric configuration and size of the edge contact area between the grinding wheel and workpiece have the heavy effects on the workpiece surface integrity. In consideration of the differences between the point grinding and the conventional high speed cylindrical grinding, the geometric and mathematic models of the edge contact area in point grinding were established. Based on the models, the numerical simulation for the edge contact area was performed. By means of the point grinding experiment, the effect mechanism of the edge contact area on the ground surface integrity was investigated. These will offer the applied theoretic foundations for optimizing the point grinding angles, depth of cut, wheel and workpiece speed, geometrical configuration and size of CBN wheel and some other grinding parameters in point grinding process.

Experimental Research on the Relationship between Surface Polishing and Fracture Strength for Ground Ceramics

2013 ◽  
Vol 770 ◽  
pp. 433-436
Author(s):  
Xin Li Tian ◽  
Jian Quan Wang ◽  
Bao Guo Zhang ◽  
Peng Xiao Wang
Keyword(s):  
Residual Stress ◽  
Fracture Strength ◽  
Ground Surface ◽  
Residual Tensile Stress ◽  
Residual Stress Field ◽  
Polishing Process ◽  
Machined Surface ◽  
X Ray ◽  
Surface Polishing ◽  
The Relationship

Fracture strength is one of the key mechanics performances for engineering ceramics products, greatly influenced by the microscopic topography and residual stress field of ground surface. In this work, several testing equipments, such as the metallurgical microscope, surface profiler and X ray residual stress tester were introduced to investigate the relationships between microscopic topography, surface roughness, residual stress and fracture strength of ground ceramics, after the surface grinding and mechanical polishing. The experimental results show that a smoother machined surface with low roughness and residual stress is obtained through polishing with absolute alcohol for 20 minutes; the fracture strength of Si3N4SiC and Al2O3 are increased by 6.64%8.18% and 6.58% respectively, comparing to the ceramics without polishing; the surface stress concentration and residual tensile stress of polished ceramics are both reduced after an appropriate time of polishing process, which causes a certain improvement of ground fracture strength.

Tribological Characteristic of Tool Steel Surface Layer Alloyed Using Laser

2020 ◽  
Vol 308 ◽  
pp. 110-118
Author(s):  
Mirosław Bonek ◽  
Eva Tillová
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Structural Changes ◽  
Dendritic Structure ◽  
High Speed Steel ◽  
Beam Power ◽  
Ceramic Phase ◽  
Structural Mechanism ◽  
Conventional Heat Treatment ◽  
The Impact

The article presents the results of research on the impact of laser surface treatment on selected steel properties. The laser treatment consisted of remelting and alloying high speed steel using hard ceramic phase powders. A high-power diode laser was used in the experiment to examine the effect of parameters such as beam power and powder type on the structure and properties of the surface layer. A structural mechanism was observed consisting in obtaining, after laser processing, a super fine crystalline structure and a dendritic structure at the remelting zone. Structural changes have been found to be associated with improved properties such as hardness, microhardness and wear resistance. Steel treated with conventional heat treatment was used as a comparative material.

Experimental Study on Splashing During Liquid Jet Impingement Onto a Liquid Film

2016 ◽  
Author(s):  
Zhan Yi ◽  
Naoki Oya ◽  
Koji Enoki ◽  
Tomio Okawa ◽  
Shuji Ohno ◽  
...  
Keyword(s):  
Liquid Film ◽  
High Speed ◽  
Nuclear Power ◽  
Jet Impingement ◽  
Liquid Jet ◽  
Jet Engine ◽  
Transition Length ◽  
The Impact ◽  
The Relationship ◽  
Fire Accident

A liquid jet is of considerable importance in many industrial fields including jet cleaning, jet engine and combustion. As an important example, the Monju nuclear power plant in Japan experienced a sodium leak in 1995. This led to a fire accident because the sodium reacted with oxygen in the air. To predict the significance of the fire accident, accurate evaluation of the amount of splashed droplets caused by the sodium jet impingement is of great importance. In this work, the relationship between the condition of a liquid jet and the amount of splashed droplets is explored experimentally. In the experiments, a liquid jet was emanated vertically downward from a circular nozzle onto a liquid film formed on a horizontal plate. Visualization using a high speed camera was performed to observe the condition of the liquid jet. From the nozzle, the mode of the liquid jet changed jet, lump and drop. Here, the jet mode means the continuous jet with smooth surface, the lump mode the continuous jet with disturbed surface and the drop mode the broken jet. Dependences of the transition length to each mode on the important parameters such as the jet velocity and the nozzle diameter were investigated. Measurement was also conducted for the splash ratio that is defined as the ratio of the amount of splashed droplets to the jet flow rate. It was found that the splash ratio is high when the liquid jet is in the drop mode at the impact point. It was shown that the splash ratio can be correlated well as a function of the impact Weber number and the Strouhal number of the droplets impinging the liquid film.

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