• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
• /
• pp.172-179
• /
• 1999

As the martensite structure cause fracture failure during drawing from 5.5mm rod to 3.05mm dia. wire without additional heat treatment, the optium cooling condition to inhibit the occurrence of martensite was investigated. In order to get SAE9254+V quality, the effects of alloying element, vanadium on the mechanical properties were investigated. Based upon CCT and TTT curves and the results form cooling test in mill, optimun cooling was found in the condition of the laying head temp of 780$^{\circ}C$ and of the conveyor speed at 0.15m/sec with the whole cover closed. The wire rods produced under the condition showed the best mechanical properties of 120kg/$\textrm{mm}^2$ in TS and 50% in RA, having an excellent drawability. In vanadium added steels, tensile strength was improved without degrading elongation and charpy impact value. That means the strengthening by vanadium is mainly due to the grain refinement by the fine precipitates during tempering process.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.293-295
• /
• 2003

KEPCO's high voltage distribution power line laid under the ground near to the J-booster pumping station that supply water for living. Lightening rod equipment does not installed at the J-booster pumping station because KEPCO's over head ground wire for protection functions as a lightening rod equipment. In this study, it is concerned whether KEPCO's over head ground wire for protect the distribution power line affect to the J-booster pumping station which is installed for reduce the damage from the direct and indirect lightening. If KEPCO's protection area does not affect to the J-pumping station, it is plan to examine the construction method of lightening rod protection angle and lightening rod equipment and to suggest the optimum protection plan using the surrounding structure based on the suitability of protection area.

• 한국산학기술학회논문지
• /
• 제12권3호
• /
• pp.1105-1110
• /
• 2011

직경 400mm 순티타늄 잉고트(Gr2)를 제작하고 성분 분석한 결과 산소함량이 0.073wt%이고 철함량이 0.03wt%로서 ASTM Gr.2 규격을 만족하였다. 이들을 가공하여 42mm 선재를 만들고 18단 열간 압연하여 9mm 선재를 만들었다. 10단 열간 가공한 15.8mm 선재를 표면에서 부터 중심부로 가면서 경도 분석한 결과 Hv150~200로서 거의 일정한 값을 나타내고 있었다. 최종 9mm 선재는 열간 압연기에 인입시 온도에 따라 항복강도와 연신율은 달랐지만 인장강도는 근사한 값을 나타내었으며 모두 ASTM B863규격을 만족하였다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2009년도 추계학술대회 논문집
• /
• pp.169-172
• /
• 2009

Multiple scale modeling has been applied to predict defect shape change during the wire rod rolling process. The size difference between bloom and defect prevent using usual FEM approaches due to the enormous number of elements required to depict the defect. The newly developed multiple scale model can visualize defect shape changes during the multi stands rolling process. The defect positioned at the top and side of bloom are smoothed out but the one at the middle evolved as folding or remained as crack. This approach can be used for defect control with roll shape design and initial bloom shape.

• 제어로봇시스템학회논문지
• /
• 제17권7호
• /
• pp.647-650
• /
• 2011

This paper presents the development of roll replacement robot system for wire-rod press rolls. The roll replacement robot system consist of a palletized railway truck, a 6-DOF industrial robot manipulator, a roll changing tool and a hydraulic power system. Results of simulation and pilot experiment show the roll changing task can be successfully automated using proposed robot system.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
• /
• pp.272-278
• /
• 1999

Tungsten Carbide(WC) Roll is widely used in finishing stands of wire rod mill. This report is about the manufacturing method of WC roll with excellent wear resistance. To enhance wear resistance, WC content has been increased to the maximum extent while binder content such as Co, Ni, Cr has been minimized. Part of WC is replaced with TiC having more wear resistant than WC. WTiC powder has been used to prevent weight unbalance resulting from the difference of specific weight when adding TiC. The roll manufactured by this method, is having more wear resistance than the existing rolls when applying to the final stand of the finishing mill. This report shows that WC is the critical factor of wear resistance in WC rolls and an approprite amount of TiC effects wear resistance and when adding TiC, using WTiC powder is better.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 D
• /
• pp.2516-2518
• /
• 2000

In order to reduce the trimming loss for water cooling zone next to finishing block mill in wire rolling, the operational data related to the crop length control of uncooled region was acquired and analyzed. The time deviation of water cooling spray nozzles and the immoderate preset length of uncooled wire rod result in the excessive trimming loss. Therefore, the preset length of uncooled wire rod at each cooling zone are established. The test results of #3 wire rolling mill turned out to be good enough to be expected to increase the ratio of products about 0.15% and establish operational standards of cooling zone.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2008년도 추계 학술발표회
• /
• pp.910-920
• /
• 2008

In Korea, more than 70% of the territory consists of mountains. Therefore, the construction of roads and railways has generally involved with a steep rock slope in which the event of rockfalls are often occurred due to the weathered rock conditions and rainfalls etc. This is dangerous when the rock falls into the road and railway on which vehicles and trains are running. In order to prevent such rockfalls, the rockfall protection fence consisting of post, wire rope, and PVC coating steel net has most used at the bottom of rock slopes. In a general practice, an absorbing rockfall energy, 50kJ is specified by the Ministry of Construction and Transportation. However, questions still remain about whether the rockfall protection fence works effectively or not. In this study, a typical wire rope used in the standard rockfall protection fence was replaced by the high carbon steel wire rod and to validate its capacity of rockfall energy absorbing the field rockfall tests were conducted. The testing results show that a new rockfall protection fence using the high carbon steel wire rods can absorb the rockfall energy more than 50kJ and 20% of construction cost was saved in comparison with the previous rockfall protection fence.

• 한국산업융합학회 논문집
• /
• 제25권2_2호
• /
• pp.263-269
• /
• 2022

In this study, the optimal support position determination and stability determination of the wedge wire screen were performed for the production of the wedge wire filter screen with improved mesh screen. In order to manufacture a filter screen using a wedge wire, the support rod wedge wire is first installed according to the filtering capacity, and then spot welding is performed while rotating the profile wire. In the existing manufacturing method, it was manufactured using a 3m rod wedge wire and then cut according to dimensions, but it required the manufacture of a 6m cylindrical screen. Due to the increase in wedge wire length, it is difficult to manufacture stress concentration at sagging and fixed positions. In order to shorten the time of analysis, a single wedge wire was applied instead of a plurality of wedge wires. The reliability and validity of the interpretation were presented and the results were derived. After selecting the support point at the 2m position, structural analysis was performed on the entire filter screen to confirm stability.The purpose of this study is to identify the maximum deflection of the wire for the production of a 6m wedge wire screen and secure design basic data so that it can work safely through optimal support.

• Nuclear Engineering and Technology
• /
• 제48권2호
• /
• pp.376-385
• /
• 2016

A hexagonally arrayed 37-pin wire-wrapped rod bundle has been chosen to provide the experimental data of the pressure loss and flow rate in subchannels for validating subchannel analysis codes for the sodium-cooled fast reactor core thermal/hydraulic design. The iso-kinetic sampling method has been adopted to measure the flow rate at subchannels, and newly designed sampling probes which preserve the flow area of subchannels have been devised. Experimental tests have been performed at 20-115% of the nominal flow rate and $60^{\circ}C$ (equivalent to Re ~ 37,100) at the inlet of the test rig. The pressure loss data in three measured subchannels were almost identical regardless of the subchannel locations. The flow rate at each type of subchannel was identified and the flow split factors were evaluated from the measured data. The predicted correlations and the computational fluid dynamics results agreed reasonably with the experimental data.