http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
0.2% C강의 미세조직에 따른 3-body 연삭마멸 특성 연구
윤나래(N. R. Yoon),김종철(J. C. Kim),정영중(J. -Y. Jeong),권혁우(H. W. Gwon),김용석(Y. -S. Kim) 한국소성가공학회 2011 한국소성가공학회 학술대회 논문집 Vol.2011 No.5
Abrasive wear behavior of 0.2 wt. % C steel with different microstructures was studied. The steel was heat treated to obtain various microstructures under different conditions. Three-body abrasive wear tests were carried out using a ball-cratering abrasive wear tester at fixed load of 0.2 N. Sliding speed and wear distance adopted were 0.05 m/sec and 50 m, respectively. A bearing steel ball was utilized as a counterpart. SiC particles of size approximately 4 ㎛ were used as the abrasive medium. The slurry concentration and feed rate were 0.75 g/ml and 1.15 g/min, respectively. The wear crater was examined using SEM, FESEM, and a surface profilometer to investigate the wear mechanism of the steel. It was found that the abrasive wear resistance was proportional to initial hardness of the heat treated steel.
연마제의 크기와 미세조직에 따른 0.18 wt. % C 탄소강의 3 - body 연삭마멸 특성
윤나래(N. R. Yoon),정영중(Y.-J. Jeong),김종철(J. C. Kim),권혁우(H. W. Gwon),김용석(Y.-S. Kim) 한국소성가공학회 2011 한국소성가공학회 학술대회 논문집 Vol.2011 No.10
Three-body abrasive wear behavior of 0.18 wt % C steel was investigated using a ball-cratering tester. Silicon carbide of various sizes was used as an abrasive. Wear test conditions were optimized to ensure three-body abrasive wear preventing two-body abrasive wear during the test. The abrasive was supplied as a slurry form, of which the concentration was 0.75 g/ml. Sliding distance, speed (ball-rotation speed) and normal load were fixed as 50 m, 0.05 m/s, and 0.2 N, respectively. Before the abrasive wear test, 0.18 wt % C steel was heat treated under various conditions to vary its microstructure. Effect of the microstructure as well as the abrasive-particle size on the wear was investigated. It was found that the abrasive wear behavior did not depend on a specific parameter such as hardness; besides, the effect of microstructure and abrasive-particle size was significant in determining the wear of the steel.
AISI 521000 강의 미세조직 변화(펄라이트와 베이나이트)에 따른 미끄럼마멸 특성
윤나래(N. R. Yoon),김종철(J. C. Kim),김용석(Y.-S. Kim) 한국소성가공학회 2010 한국소성가공학회 학술대회 논문집 Vol.2010 No.5
Dry sliding wear behavior of AISI 52 100 steel was characterized to explore the effect of microstructure on the wear of the steel. Isothermal heat treatment of the bearing steel was carried out to obtain full pearlitic and bainitic microstructures. Pin-on-disk wear tests of the steel were performed at a fixed load of 100 N in the air. Sliding speed and wear distance were 0.1 m/sec and 300 m, respectively. The alumina ball was utilized as a counterpart. Worn surfaces, wear debris and cross-sections of the worn surfaces were examined with SEM to investigate the wear mechanism of the steel. Tensile properties and hardness of the steel were also evaluated. Wear rate of the steel was correlated with the measured mechanical properties and effect of the microstructure was explored. It was found that neither the hardness nor the strength solely does characterize the wear of the steel. The microstructure strongly influenced the wear rate, and the specimen with the pearlitic microstructure showed higher wear resistance than the bainitic microstructure.
열처리된 2024A1 합금의 석출물이 건식 미끄럼 마멸 특성에 미치는 영향
권혁우(H.W. Gwon),윤나래(N.R. Yoon),김종철(J.C. Kim),정영중(Y.-J. Jung),김용석(Y.-S. Kim) 한국소성가공학회 2011 한국소성가공학회 학술대회 논문집 Vol.2011 No.5
In the present study, the effect of precipitates on the dry sliding wear characteristics of 2024 A1 alloy was investigated. Dry sliding wear tests were performed on the as-received (T4) and solution treated 2024 A1 alloy, and their wear behavior was compared in connection with work hardening behavior during the wear. Special attention was given to the relationship between strain hardening and the precipitates, which changed the wear rate and characteristics of the alloy. Work-hardening at the wearing surface is the most important factor during sliding wear of metallic materials, since the strain hardening affects the formation of a deformation layer at the surface. The deformation layer is often related with the formation of wear particles which are detached particles from the layer. The hardened deformation layer also acts as a protecting layer that resists further progress of wear. The relationship between the microstructure and the strain-hardening at the wearing surface was explored, which explained the wear-rate variation with the microstructure.
0.25 wt.% C 저합금강의 미끄럼 마멸거동에 미치는 합금원소의 영향
김종철(J. C. Kim),윤나래(N. R. Yoon),김용석(Y. S. Kim) 한국소성가공학회 2011 한국소성가공학회 학술대회 논문집 Vol.2011 No.5
The purpose of this study is to investigate the effect of alloying elements on dry sliding wear behavior of the 0.25 wt. % C low-alloy steel. To examine the effect of alloying elements, 11 kinds of steels were fabricated by varying the amount of Cr, B and Ti. Dry sliding wear tests have been carried out using a pin-on-disk wear tester at the constant load of 100 N and sliding speed of 0.1 m/s. Of all the specimens Cr, B and Ti alloyed steels showed high wear resistance compared with the other steels. The higher wear resistance of the steels were attributed to their higher dynamic strain-hardening capacity during the wear.
AISI 52100 베어링강의 미세조직에 따른 3-body 연삭마멸거동
정영중(Y. -J. Jeong),김종철(J. C. Kim),권혁우(H. W. Gwon),윤나래(N. R. Yoon),김용석(Y. -S. Kim) 한국소성가공학회 2011 한국소성가공학회 학술대회 논문집 Vol.2011 No.5
This investigation was performed to reveal the microstructural effect on 3-body abrasive wear behavior of the AISI 52100 bearing steel. The steel was heat treated under different conditions to obtain bainite and pearlite microstructures. The bainite and pearlite microstructures were obtained by holding the solution treated specimens at 300℃ and 330℃ for 2 hours and at 650℃ and 700℃ for various period followed by water quenching, respectively. Three-body abrasive wear tests were carried out using a ball-cratering tester. Abrasive slurries of SiC particles (4 fim) suspended in water were used at constant concentration (0.75 g/ml). All tests were performed with a sliding speed of 0.05 m/s, normal load of 0.2 N and sliding distances of 50 m. The slurries were fed on to the top of the ball throughout the test at a rate approximately 1.15 g/min. The worn surfaces were observed by a stereoscopic microscope, SEM, and FESEM (field emission scanning electron microscope). The hardness of specimens was measured by a micro Vickers hardness tester. It was found that the wear resistance of the pearlite was better than that of the bainite.
0.25 wt.% C 탄소강의 미세조직 변화와 3 - body 연삭마멸 특성
정영중(Y.-J. Jeong),김종철(J. C. Kim),윤나래(N. R. Yoon),권혁우(H. W. Kwon),김용석(Y.-S. Kim) 한국소성가공학회 2011 한국소성가공학회 학술대회 논문집 Vol.2011 No.10
This investigation was performed to reveal the effect of microstructure on 3-body abrasive wear behavior of the 0.25wt.% C steel. The steel was heat treated under different conditions to obtain PF/P (Polygonal ferrite & Pearlite), AF(Acicular ferrite) and PF/TM (Polygonal ferrite & Tempered martensite) microstructures. Three-body abrasive wear tests were carried out using a ball-cratering tester. The ball was an AISI 52100 steel ball. The ball-surface was roughened by rotating on a specimen to feed slurries easily into the contact between the ball and the specimen. The roughening distance was 7.85 m. The slurry of Al2O3 particles(4μm) suspended in water with concentration of 0.75 g/ml was fed on top of the ball throughout the test at a rate approximately 1.445 g/min. All tests were performed with a normal load of 0.2N, sliding(ball rotation) speed of 0.05 m/s and sliding distance of 50 m. Microstructure of the heat treated specimens was observed by an optical micorscope, and worn surface were observed by a stereoscopic microscope and SEM (scanning electron microscop). Hardness of the stell was measured by a micro Vickers hardness tester. The PF/P microstructure showed the best 3-body-abrasive-wear resistance among the microstructures examined in the present study.
Metal-polymer Joining Method with Laser Structuring to Enhance Cross-tension Strength
S. Chey(최석영),J. Y. Choi(최준영),G. Y. Kim(김근영),J. Y. Kim(김지엽),J. Lee(이중혁),A. K. Han(한경원),D. H. Kim(김도회),J. Jeong(정준영),S. J. Hong(홍석주),N. R. Yoon(윤나래),J. H. Hwang(황준호),H. D. Kim(김현덕),Y. S. Gu(구윤식),J. W. C Korean Society for Precision Engineering 2023 한국정밀공학회 학술발표대회 논문집 Vol.2023 No.11