scholarly journals Plastic Strain Threshold Determination for White Layer Formation in Hard Turning of AISI 52100 Steel Using Micro-Grid Technique and Finite Element Simulations

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Guang-Chao Nie ◽  
Ke Zhang ◽  
Jose Outeiro ◽  
Serafino Caruso ◽  
Domenico Umbrello ◽  
...  
Keyword(s):  
Plastic Strain ◽  
Hard Turning ◽  
White Layer ◽  
Cryogenic Cooling ◽  
Cooling Conditions ◽  
Aisi 52100 ◽  
Aisi 52100 Steel ◽  
Grid Technique ◽  
Micro Grid ◽  
Strain Threshold

Abstract White layer (WL) formation in metal cutting is generally found to have negative effects on the corrosion and fatigue life of machined components. Nowadays, the mechanism of the WL formation has not been understood very well, especially about the contribution of the thermal and mechanical loadings generated by the cutting process on WL formation. The relationship between subsurface plastic strain caused by mechanical loadings and the formation of WLs is of our concern. To address this issue, WL formation in hard turning of AISI 52100 under dry and cryogenic cooling conditions is investigated by subsurface plastic strain measurement using the micro-grid technique, observed by scanning electron microscope (SEM). Due to the considerable low temperature, WL is mainly generated by the mechanical effect rather than the thermal one, and this hypothesis is supported by physically based finite element method (FEM) simulations. From the investigations, we discover the existing plastic strain threshold, which governs the occurrence of WL in hard turning of AISI 52100 steel under cryogenic cooling conditions.

scholarly journals Surface Integrity of AISI 52100 Steel during Hard Turning in Different Near-Dry Environments

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ajay Chavan ◽  
Vikas Sargade
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
Hard Turning ◽  
Vortex Tube ◽  
White Layer ◽  
Bearing Steel ◽  
Hybrid Nanofluid ◽  
Aisi 52100 ◽  
Aisi 52100 Steel ◽  
Cooling And Lubrication

AISI 52100 hardened bearing steel is popular in many industrial applications due to its excellent wear resistance and high strength. Therefore, a high level of surface integrity of the same is the utmost important requirement to enhance fatigue life. Machining of hardened AISI 52100 steel is difficult because severe plastic deformation and generation of high temperature alter the surface metallurgy of the machined component and hamper the tool life. The present investigation includes a comparative analysis of surface integrity of AISI 52100 bearing steel during hard turning under different near-dry environments, namely, dry, Minimum Quantity Cooling and Lubrication (MQCL), Compressed Chilled Air by Vortex Tube (CCAVT), and Hybrid Nanofluid Minimum Quantity Cooling and Lubrication (Hybrid NF-MQCL). Soyabean (a vegetable) oil is used as cutting fluid in MQCL and base fluid in Hybrid NF-MQCL environments. To prepare hybrid nanofluid, two different nanoparticles Al2O3 and MWCNT, are used. The chilled air is generated through a vortex tube. The surface integrity of AISI 52100 steel was studied in terms of microhardness, the thickness of the white layer, surface roughness (Ra), and residual stresses. Higher cutting speed and feed show positive and negative correlation on surface integrity of AISI 52100 steel, respectively. Hybrid nanofluid MQCL exhibits the lowest surface roughness (0.34 μm), microhardness (625 Hv0.1), compressive residual stresses (−168 MPa), and thin white layer (0.9 μm) in contrast, and dry machining shows higher surface roughness, microhardness, tensile residual stress, and thick white layer. In comparison, MQCL and CCAVT are found to be intermediate. It is found that hybrid nanofluid MQCL enhances the overall performance of the machined surface as compared to other near-dry techniques.

scholarly journals Machining force comparison for surface defect hard turning and conventional hard turning of AISI 52100 steel

2021 ◽  
Vol 13 (3) ◽  
pp. 205-214
Author(s):  
P. U MAMAHESWARRAO ◽  
D. RANGARAJU ◽  
K. N. S. SUMAN ◽  
B. RAVISANKAR
Keyword(s):  
Hard Turning ◽  
Surface Defect ◽  
Cutting Speed ◽  
Tool Geometry ◽  
Depth Of Cut ◽  
Nose Radius ◽  
Aisi 52100 ◽  
Machining Force ◽  
Aisi 52100 Steel ◽  
The Impact

In this article, a recently developed method called surface defect machining (SDM) for hard turning has been adopted and termed surface defect hard turning (SDHT). The main purpose of the present study was to explore the impact of cutting parameters like cutting speed, feed, depth of cut, and tool geometry parameters such as nose radius and negative rake angle of the machining force during surface defect hard turning (SDHT) of AISI 52100 steel in dry condition with Polycrystalline cubic boron nitride (PCBN) tool; and results were compared with conventional hard turning (CHT). Experimentation is devised and executed as per Central Composite Design (CCD) of Response Surface Methodology (RSM). Results reported that an average machining force was decreased by 22% for surface defect hard turning (SDHT) compared to conventional hard turning (CHT).

Effect of Cutting-Edge Geometry and Workpiece Hardness on Surface Residual Stresses in Finish Hard Turning of AISI 52100 Steel

1999 ◽  
Author(s):  
Jeffrey D. Thiele ◽  
Shreyes N. Melkote ◽  
Roberta A. Peascoe ◽  
Thomas R. Watkins
Keyword(s):  
Residual Stresses ◽  
Hard Turning ◽  
Cutting Edge ◽  
Phase Changes ◽  
Edge Geometry ◽  
Surface Residual Stresses ◽  
Aisi 52100 ◽  
High Feed ◽  
Aisi 52100 Steel ◽  
Finish Hard Turning

Abstract An experimental investigation was conducted to determine the effects of tool cutting-edge geometry and workpiece hardness on surface residual stresses for finish hard turning of through-hardened AISI 52100 steel. Polycrystalline cubic boron nitride (PCBN) inserts with representative types of edge geometry including “up-sharp” edges, edge hones, and chamfers, were used as the cutting tools in this study. This study shows that tool edge geometry is highly influential with respect to surface residual stresses, which were measured using x-ray diffraction. In general, compressive surface residual stresses in the axial and circumferential directions were generated by large edge hone tools, for longitudinal turning operations. Residual stresses in the axial and circumferential directions generated by small edge hone tools are typically more tensile than stresses produced by large edge hone tools. Microstructural analysis shows that thermal effects are significant at high feed rates, based on the presence of phase changes on the workpiece surface. At high feed rates, compressive stresses correlate with continuous white layers and tensile stresses correlate with over-tempered regions on the surface of the workpiece. Mechanical effects play a larger role at low feed rates, where phase changes are not observed to a significant degree. For these cases, large edge hone tools generally produce more compressive values of residual stress than small edge hone tools.

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