• Journal of the Korean Society for Precision Engineering
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• v.15 no.7
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• pp.36-43
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• 1998

Surface roughness of cold rolled steel sheet as well as the coating technique itself is quite important in obtaining high image clarity of electronic products and car outer panels. Especially, surface characteristics of steel sheet have acquired increasing attention from the steel and automotive industries. While the influence of such characteristics on paintability formability and painted surface appearance is important in defining steel surface requirements for automotive industries. Therefore this paper is dedicated primarily to the issue of paint appearance and reviews for improvement of roughness and peak count about the surface of work roll for the actual temper mill. The conclusions were obtained as follows ; 1) Roughness and peak count about the surface of steel sheet is strongly affected by surface condition of work roll. 2) The electro-discharge textured roll has more uniform roughness distribution than shot blasted roll and it's painted appearance of steel sheet has more improvement than that of the shot blasted because it has more harmonic wave roughness, and the higher peak count of surface roughness.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.2
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• pp.68-74
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• 2013

In this paper, an average surface roughness, $R_a$, was measured by optical measurement and its mathematical model according to spindle speed and feedrate was obtained by least square method. Also, its result is compared and investigated with real measured average surface roughness. The optical measurement of surface roughness is performed by CLSM(confocal laser scanning microscope) and the captured HEI(height encoded image) data is used as an original data for the generation of average surface roughness and its mathematical plane or contour surface of surface roughness. Using this polynomial model with two independent variables, the behavior of an average surface roughness is investigated and analyzed with an experimental modeling of least square algorithm. And it can be used for the prediction of $R_a$ in different condition of machining.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.541-544
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• 1993

This paper attempts to propose new procedures to evaluate roughness of ground metallic surface in the range of 1-10.mu.m from data gained by an optical, in-process measurement of the surfaces. Studies are made to process the data of reflected lights pointed at the surface to be measured. Results obtained are compared with those of measurement by stylus roughness meter. Correlations between the two types of roughness measurement are well. The proposed method can be used as a sensor for a polishing robot.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.2
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• pp.37-43
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• 2004

High speed machining is a machining process which cuts materials with the fast movement and rotation of a spindle in a machine tool. It reduces machining time because of the high feed and the high speed of a spindle. In addition it gets rid of post processes for high precision machining. When the high speed machining is applied to especially hardened steel, operators should select the proper parameters of machining. This can produce machining surfaces which is qualified with good surface roughness. This paper presents a method for selecting machining parameters to minimize surface roughness with high speed machining in cutting the hardened steels. Experimental data for surface roughness are collected in a machining shop based on the cutting feed and the spindle rotation. The data fits in hi-cubic polynomial surface of mathematical form. From the model this research minimize the surface roughness to find the optimal values of the feed and the spindle speed. This paper presents a program which automatically generates optimal solutions from the raw data of experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.283-286
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• 2002

In fiber optic sensor, the error of the measurement is influenced by the surface roughness of the target and surroundings, especially the outside light. To reduce or modify this error, the sensitivity of the fiber optic sensor and the noise change by the surface roughness of the target should be known. The purpose of this paper is to observe the sensitivity of the fiber optic sensor and the noise according to the surface roughness of the target.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.131-136
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• 2000

This paper is concerned with the surface roughness and the bending strength of ground workpiece in ZrO2 ceramic grinding. Surface roughness was measured with surface tracer and bending strength value was obtained by three-point bending test on machining center using tool dynamometer. Grinding experiments were carried out to examine the effects of grinding conditions including diamond mesh size, table speed, and depth of cut on ground surface roughness. The correlation between surface roughness and bending strength was also inspected. The experimental results indicate that the rougher surface is produced as the mesh size of diamond wheel is reduced and table speed is increased, but surface roughness is not affected by depth of cut. The values of bending strength decrease as the values of Ra, Rmax and Ku increase.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.465-470
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• 2000

This paper is concerned with the surface roughness and the bending strength of ground workpiece in ZrO2 ceramic grinding. Surface roughness was measured with surface tracer and bending strength value was obtained by three-point bending test on machining center using tool dynamometer. Grinding experiments were carried out to examine the effects of grinding conditions including diamond mesh size, table speed, and depth of cut on ground surface roughness. The correlation between surface roughness and bending strength was also inspected. The experimental results indicate that the rougher surface was produced as the mesh size of diamond wheel is reduced and table speed is increased, but surface roughness is not affected by depth of cut. The values of bending strength decrease as the values of Ra, Rmax and Ku increase.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.1 no.1
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• pp.133-140
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• 2002

The object of this paper is to predict the surface roughness using the experiment equation of surface roughness, which is developed with a full factorial design in turning. $3^3$ full factorial design has been used to study main and interaction effects of main cutting parameters such as cutting speed, feed rate, and depth of cut, on surface roughness. For prediction of surface roughness, the arithmetic average (Ra) is used, and stepwise regression has been used to check the significance of all effects of cutting parameters. Using the result of these, the experimental equation of surface roughness, which consists of significant effects of cutting parameters, has been developed. The coefficient of determination of this equation is 0.9908. And the prediction ability of this equation was verified by additional experiments. The result of that, the coefficient of determination is 0.9718.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.467-474
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• 2004

This paper presents the results of an experimental investigation for the effect of radiant heat on the evaporation cooling of water droplet in the process of fire extinguishing. The experiments are mainly focused on the surface temperature, the surface roughness and the droplet diameter. The range of surface temperature is T$_{s}$ =80－14$0^{\circ}C$, surface roughness is R$_{a}$=0.08－0.64 ${\mu}{\textrm}{m}$ and the droplet diameter is $\Phi$=3.0 mm in the radiation. The results show that the evaporation time is shorter for the larger surface roughness and the volume of droplet increased when the surface roughness is 0.64 ${\mu}{\textrm}{m}$ at the surface temperature 127$^{\circ}C$. When the surface roughness is 0.64 ${\mu}{\textrm}{m}$, the heat flux is larger than the surface roughness is 0.08 ${\mu}{\textrm}{m}$ at the surface temperature 81$^{\circ}C$.>.>.

• KSTLE International Journal
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• v.2 no.2
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• pp.133-137
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• 2001

This paper investigates the correlation between strip surface roughness and the surface of the work roll. As the actual temper mill(TM) is used, this data will be adopted to another actual temper mill for the application and operation of this experiment. Conclusions are as follows: Electro-discharge texturing(EDT) roll has homogeneous roughness distribution and shape, and also a sinuous peak surface and the life is 2 times longer than that of shot blast texturing(SBT) method. And the higher surface roughness of work roll, the more time is necessary at the EDT method. In the SBT method without the correlation of roughness, but impeller rotation speed with an uncontrollable peak count. The roughness of SBT roll is irregularity compared to that of EDT roll because the work roll roughness is transferred to the strip which was temper rolled, and produces a more desirable image and greater clarity to the color painted steel sheet.