Research on Tribological Properties of Environment-Friendly Nano-MoS2 Water-Based Rolling Liquid

2020 ◽  
Vol 861 ◽  
pp. 349-353
Author(s):  
Yan Li ◽  
Ren Dong Liu ◽  
Lei Xia ◽  
Rong Sheng Sun ◽  
Jian Jun Zhang ◽  
...  
Keyword(s):  
Surface Quality ◽  
Laser Scanning ◽  
Surface Defects ◽  
Rolled Strip ◽  
Environment Friendly ◽  
Lubrication Performance ◽  
Water Based ◽  
The Coefficient Of Friction ◽  
Water Base

In this research, the four-ball tribometer was examined to evaluate the tribological behavior of environment-friendly nano-MoS2 water-based rolling liquid. This experimental method is used to measure the maximum non-seizure load (PB) and the coefficient of friction (μ). The newly introduced parameter ω can be combined with PB and μ to evaluate the tribological performances of the rolling liquid comprehensively. The rolling lubrication performance of nano-MoS2 water-base lubricant was investigated using a single stand 4-high reversing rolling mill. The surface morphologies and rolling textures of the samples were measured by laser scanning confocal microscope after cold rolling. The results show that when the concentration of nano-MoS2 is 0.4wt.%, the water-based rolling liquid has excellent tribological and lubricating properties. Meanwhile, compared with the surface quality of the rolled strip under other lubrication conditions, the surface quality of the cold-rolled strip using 0.4wt% nano-MoS2 rolling liquid as the lubrication condition is smooth without visible surface defects.

A study of conditions of surface defects formation when bar rolling at a bar and wire mill and methods of their elimination

2021 ◽  
Vol 77 (10) ◽  
pp. 1053-1059
Author(s):  
I. A. Pankovets ◽  
V. I. Voznaya ◽  
A. V. Vedeneev ◽  
M. N. Vereshchagin
Keyword(s):  
Temperature Gradient ◽  
Surface Quality ◽  
Surface Defects ◽  
Temperature Deformation ◽  
Controlled Cooling ◽  
Wire Mill ◽  
The Core ◽  
Local Overheating ◽  
Rolling Production

Quality of long products surface is an important consumer property of it. In the process of measures elaboration aimed at the increase of long products surface quality, in particular of bars produced at the mill 370/150 of ОJSC “BMZ – managing company of holding “BMK”, studies were accomplished by metallographic laboratory. It was established that defects being revealed at the bars finishing, don’t relate to the quality of continuously casted billet (CCB), but formed in the process of deformation. Studies of the mechanism of surface defects formation on hot-rolled bar of rolling origin – deformation fissure and wrinkles were carried out. Results of numerical simulation of rolling in roughing group of stands at various temperature-deformation parameters presented. Regularities of formation of surface defects on the bar in the finished product were revealed. It was shown that the reason of the surface defects of rolling origin – deformation fissure and wrinkles was a high temperature gradient between the core and the surface of billet, originated from local overheating of surface in the angles zone of CCB resulted in nonuniformity of drawing out of different layers of the billet being deformed. To eliminate the defects, minimum possible temperature gradient between the surface and the core of a billet by controlled rolls cooling should be provided. By calculation, the maximum permissible temperature of the working surface of the rolls of the rough group of stands was established, and empirically the actual temperatures of the rolls with the current production technology, as well as the temperature of the rolls support bearings seats of the rolls were measured. The technical and technological possibilities for improving of rolling technology on a bar and wire mill in order to improve the surface quality of rolled bars were demonstrated. The existing technology was adjusted and new technological modes of rolling with controlled cooling of the rolls were established, which made it possible to significantly reduce the rejection of the finished product due to defects in rolling production. A device was proposed for the roughing group of stands, which enables to minimize the ingress of coolant onto the bar rolled.

Evaluation of Stamping Lubricants in Forming Galvannealed Steels for Industrial Application

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Soumya Subramonian ◽  
Nimet Kardes ◽  
Yurdaer Demiralp ◽  
Milan Jurich ◽  
Taylan Altan
Keyword(s):  
Preliminary Test ◽  
Work Piece ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Deep Draw ◽  
Fe Simulations ◽  
Water Based ◽  
The Coefficient Of Friction ◽  
Synthetic Water

Lubrication is one of the process variables that affect the quality of stamping sheet materials. Using a good lubricant can significantly reduce scrap rate and/or improve the quality of stamping. In this study, different types of lubricants were evaluated using strip draw test (SDT) and deep draw test (DDT) for stamping of galvannealed steel sheets. Finite element (FE) simulations were carried out to determine the coefficient of friction at tool-work piece interface during deep drawing under different lubrication conditions and blank holder forces. Flow stress data of materials under biaxial load which are used in FE simulations are obtained by viscous pressure bulge tests. SDT was used as a preliminary test to evaluate the relative performance of the lubricants. Lubricants that showed good performance in this test were tested using DDT. Dimensions of the formed strips and cups and the maximum applicable blank holder force to draw parts without fracturing were the criteria used for evaluation of lubricants in both tests. In general, it was possible to form cups with higher blank holder force when synthetic/water-based lubricants were applied to the sheet. In conclusion, evaluated synthetic/water-based lubricants had better lubricity than petroleum-based lubricants.

Research Progress of Improving Surface Quality of Microcellular Foam Injection Parts

2011 ◽  
Vol 66-68 ◽  
pp. 2010-2016 ◽  
Author(s):  
Yue Wang ◽  
Guang Hong Hu
Keyword(s):  
Injection Molding ◽  
Surface Quality ◽  
Dimensional Stability ◽  
Surface Defects ◽  
Research Progress ◽  
Microcellular Foam ◽  
Counter Pressure ◽  
Foam Injection Molding ◽  
Application Scope

Microcellular foam injection parts have many advantages such as saving material and energy, reducing cycle time, and processing excellent dimensional stability. Despite these advantages, the low surface quality problems limit its application scope seriously. In this study, the microcellular foam injection molding principle and some surface defects were introduced, and the technologies to improve surface quality, such as Gas Counter Pressure (GCP), Rapid Heat Cycle Molding (RHCM), and Film Insulation were summarized in detail. Finally, the prospect of CAE technologies about microcellular foam injection molding was proposed.

Recognition and Control of the Influence Factors on the Surface Defects of Cold Rolled Strip with Emulsion Lubrication

2013 ◽  
Vol 456 ◽  
pp. 498-502
Author(s):  
Yan Li ◽  
Jian Lin Sun
Keyword(s):  
Cold Rolling ◽  
Surface Quality ◽  
Surface Defects ◽  
Surface Condition ◽  
Influence Factors ◽  
Black Spot ◽  
Rolling Process ◽  
Rolled Strip ◽  
Strip Surface ◽  
Cold Rolled

In cold rolling, good surface quality should be maintained with the requirement of constant increasing productivity. Oil-in-water (O/W) emulsions are widely used in cold rolled strips due to their good characteristics as lubricants and coolants. The strip surface defect is one of the central quality problems in the rolling process. A poor strip surface quality after cold rolling may have a large impact on the downstream process, like annealing, galvanization and painting. The surface condition could be deteriorated in many forms affected by various factors. However, few reports focused on the effect of the lubricating property of emulsion on the final surface quality. In this paper, the general surface defects of cold rolled strips such as watermark defects, black spot defects, heat scratches and corrosion defects were analyzed by scan electron microscope (SEM) and energy spectrum analysis (EDS) and the morphology and composition of the defects have been researched. The reason of the surface defects generated is analyzed, and the factors which introduce the surface defects during rolling process are presented. Therefore, it has an important significance to identify the features of the surface defects and put forward the solution measures.

An increase in the surface quality of hot-rolled strip

Metallurgist ◽  
1963 ◽  
Vol 7 (5) ◽  
pp. 223-224
Author(s):  
M. A. Benyakovskii ◽  
O. A. Mel'nikov ◽  
L. N. Chukhlova ◽  
S. K. Glukhov
Keyword(s):  
Surface Quality ◽  
Rolled Strip ◽  
Hot Rolled Strip ◽  
Hot Rolled

Design of Automatic Detection Device for Steel Bar Surface Defects

2012 ◽  
Vol 532-533 ◽  
pp. 390-393 ◽  
Author(s):  
Jian Chuan Zhang ◽  
Wu Bin Li ◽  
Chang Hou Lu
Keyword(s):  
Image Processing ◽  
Surface Quality ◽  
Automatic System ◽  
Surface Defects ◽  
Detection System ◽  
High Luminance ◽  
Linear Ccd ◽  
Steel Bar ◽  
And Performance

To inspect the surface quality of steel bar, we designed an automatic system including linear camera and laser. Through the comparison among kinds of cameras, we select linear CCD to our system. The laser is also chosen by us with its high luminance and performance. Through a series of computation, we select the appropriate camera lens to our device. At last, we draw the whole detection system. This device has been used well and provides a good foundation for prospective image processing.

Some Observations in Grinding Surface Quality of FRCMC

2013 ◽  
Vol 770 ◽  
pp. 198-201 ◽  
Author(s):  
Xiao Yan Cao ◽  
Bin Lin ◽  
Yan Wang ◽  
Shao Lei Wang
Keyword(s):  
Surface Quality ◽  
Fiber Orientation ◽  
Surface Defects ◽  
Optical Measurement ◽  
Orientation Angle ◽  
Decisive Role ◽  
Ceramic Matrix Composites ◽  
Obtuse Angle ◽  
High Tech

FRCMCs have potential applications in aerospace and other high-tech fields. According to FRCMCs anisotropic and non-homogeneous structure, the composites surface characteristics are different from metal material. Fiber orientations play the decisive role in grinding surface quality of woven ceramic matrix composites. This paper investigates the relationship between fiber orientations and grinding surface quality. Using a non-contact optical measurement instrument, the method was developed on 2.5D SiO2/SiO2 composite. Through a series of measuring experiments, it was found that greater grinding surface quality occurred at a fiber orientation 90, but poorer grinding surface took place at a fiber orientation 0. Meanwhile there were less surface defects at acute fiber orientation angle than at obtuse angle. The research obtained will be an important technical support on improving the processing quality of FRCMC.

An Investigation on Top Surface Quality for Direct Metal Laser Fabrication

2011 ◽  
Author(s):  
Jialin Yang ◽  
Chao Xu ◽  
Yang Wang
Keyword(s):  
Surface Quality ◽  
Laser Scanning ◽  
Surface Defects ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Contributing Factors ◽  
Laser Fabrication ◽  
Scanning Area ◽  
The Stability ◽  
Manufacturing Technologies

SLS (Selective Laser Sintering) has been developing rapidly since its initial invention for non-metal materials by Texas University. Nowadays, Direct Metal Laser Fabrication (DMLF), as a variant of SLS technique, has been investigated intensively which is aimed at rapid manufacturing of end-use metal products with full functions. For describing the stability and properties of DMLF process, Top Surface Quality (TSQ) was put forward in this paper, which could be a unique and crucially important feature compared with traditional manufacturing methods. Through the systematic and detailed analysis of DMLF process using related theories of additive manufacturing technologies, it was revealed that TSQ was the key factor for controlling the stability of DMLF process and thus tailoring final properties of metallic parts. TSQ was defined as the surface morphology in macro and micro scopes in laser scanning area of unit layers during DMLF, and could be characterized by three key elements: flatness, compactness and cleanliness. Only good TSQ could ensure the stability of DMLF process and excellent performance of metal parts in theory. The flatness was the significant factor to assure the shaping during DMLF while the compactness and cleanliness are the decisive factors to assure the final properties of metal part for DMLF. As an example, the typical top surface defects and their contributing factors in DMLF for Cu-based metal powder mixtures were investigated thoroughly according to the proposed definition and requirements. Moreover, the specific controlling methods of TSQ were provided and discussed. Eventually, DMLF of three-dimensional Cu-based metal sample with complicate structure was successfully performed by taking some effective measures for adjusting TSQ parameters.

scholarly journals Experimental Research on the Surface Quality of Milling Contour Bevel Gears

2021 ◽  
Author(s):  
Mingyang Wu ◽  
Jianyu Zhang ◽  
Chunjie Ma ◽  
Yali Zhang ◽  
Yaonan Cheng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Surface Defects ◽  
Low Noise ◽  
Tooth Surface ◽  
Machining Accuracy ◽  
Machined Surface ◽  
Bevel Gears ◽  
Machined Surface Roughness

Abstract Contour bevel gears have the advantages of high coincidence, low noise and large bearing capacity, which are widely used in automobile manufacturing, shipbuilding and construction machinery. However, the quality of the tooth surface has a significant impact on the transmission accuracy of the gear, so it is of great significance to optimize the surface quality of the contour bevel gear. This paper firstly analyzes the formation process of machined surface roughness of contour bevel gears on the basis of generating machining method, and dry milling experiments of contour bevel gears are conducted to analyze the effects of cutting speed and feed rate on the machined surface roughness and surface topography of the workpiece. Then, the surface defects on the machined surface of the workpiece are studied by SEM, and the causes of the surface defects are analyzed by EDS. After that, XRD is used to compare the microscopic grains of the machined surface and the substrate material for diffraction peak analysis, and the effect of cutting parameters on the microhardness of the workpiece machined surface is investigated by work hardening experiment. The research results are of great significant for improving the machining accuracy of contour bevel gears, reducing friction losses and improving transmission efficiency.

Study on the surface quality of 60vol% SiCp/Al2024 composites with large-grained

2022 ◽  
pp. 095440622110607
Author(s):  
Po Jin ◽  
Qi Gao ◽  
Quanzhao Wang ◽  
GuangYan Guo
Keyword(s):  
Surface Quality ◽  
Surface Defects ◽  
Subsurface Damage ◽  
Micro Milling ◽  
Stress And Strain ◽  
Particle Removal ◽  
Multiple Particles ◽  
Cutting Velocity ◽  
Stress And Strain Distribution

In this paper, the finite element cutting simulation model with irregular distribution of multiple particles is established, the stress and strain distribution of SiC particles in the process of machining, as well as the material removal mechanism are analyzed. The effects of cutting velocity and feed per tooth on the surface quality of the material are also analyzed. The effect of feed per tooth on subsurface damage is revealed. The results show that in the micro-milling of SiCp/Al2024 composites, the particle removal form is mainly crushing and extraction. The surface defects of the workpiece mainly include pits, scratches, cracks, and extrusion damage. When the cutting velocity increases, the surface defects gradually change to crack, which can improve the surface quality of the workpiece. Increasing the feed per tooth will increase the surface defects of the workpiece and lead to poor surface quality. When the feed per tooth increased from 0.428 µm to 0.714 µm, the subsurface damage thickness increased from 35.2 µm to 47.3 µm.

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