Barrel plating process specification for undercoating with copper cyanate

한경호,이승범,홍인권 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.3

Barrel plating is a method of coating small parts using a horizontal type barrel, which can be operated automatically. Nevertheless, barrel plating for a plating material with a complex geometry has a problem with deviations in the coating thickness due to the supply of the plating solution through the barrel and irregular contact of the plating material and cathode. Therefore, this study examined the relationship between the barrel pore size, number of pores and open pore ratio in copper cyanide barrel plating as well as the plating characteristics in accordance with the process variables, such as the barrel rotation speed, plating temperature, plating voltage and plating time. An automobile wheel nut was selected as the plating material and barrel plating was carried out in a 4.7 L sized barrel. The optimal part charging quantity was found to be 40 ea., and the plating characteristics of the best quality for the optimal plating conditions of the barrel plating process were a plating temperature, plating voltage and rotation speed of 323 K, 1 V and 1.5 rpm in a barrel with 22.5% of open pore ratio.

MBA(Muscat Bailey A) 와인의 오크통 숙성에 따른 품질 특성

최원일,박정미,박혜진,Choi, Wonil,Park, Jung-Mi,Park, Hyejin 한국식품영양학회 2021 韓國食品營養學會誌 Vol.34 No.1

This study was conducted in order to investigate the quality characteristics of MBA wine resulting from treatment with different oak barrel maturation methods. This study focused on the maturation of wine in five different types of barrels, including a stainless-steel maturation barrel, a foreign medium-toasted oak barrel, and domestic light, medium and heavy toasted oak barrels, and looked at the resulting differences in quality characteristics between the wines. All oak barrels used for this study had a capacity of 100 liters. The results of the study revealed that the pH content increased by up to 3.86~3.93% after 9 months, and then decreased after this point. The total anthocyanin content increased up to 152.52~174.95 mg/L during a 6 month maturation period, and thereafter began decreasing in concentration, with overall anthocyanin levels tending to be higher after maturation in foreign oak barrels. Overall, functional elements tended to measure higher after maturation in foreign oak barrels as opposed to maturation in domestic oak barrels. Therefore, these results indicate that it is necessary to improve the production of domestic oak barrels in the future in order to reliably produce wines with higher levels of functional elements.

포신 내경 측정시스템 개선을 통한 공정품질 향상

박영민,배인화,김상부 한국품질경영학회 2023 품질경영학회지 Vol.51 No.4

Purpose: The variation of the internal diameters of gun barrel incurs a lot of reworks in gun barrel manufacturing process and the significant quality problem of gun barrel. And it is likely to stem from the current measurement system for the internal diameter of gun barrel and the related manufacturing process as well. The purpose of this study is to improve the gun barrel manufacturing process through improving measurement system. Methods: The improved measurement system using laser can measure the internal diameters of gun barrel more accurately, and the properly adjusted honing process reduces the variation of internal diameters of gun barrel. Results: Comparing the mean square error of internal diameters for 6 gun barrels measured before and after process improvement shows that the variation of gun barrel internal diameters was significantly reduced after the process improvement. Conclusion: The introduction of improved measurement system for the internal diameters of gun barrel and the adjustment of related honing process results in the reduction of reworks of gun barrels and their internal diameter variations.

개인화기 총열 표면처리 및 시험에 관한 연구

채제욱(Chae Je-Wook),김인우(Kim In-Woo),이영신(Lee Young-Shin) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4

This paper includes the comparative study between Cr plating and nitriding process with an aim at improving corrosion, wear and maintainability for KNR(Korean Next Generation Rifle) 5.56㎜ barrel. The endurance test was conducted to compare the performance of standard barrel, Cr plating barrel and nitriding barrel. Main activities are described as follows; optimal Cr plating and nitriding process set-up for KNR 5.56㎜ barrel; durability test of each barrel(20,000 rounds); salt water i㎜ersion test; dispersion, initial velocity, inner diameter data acquisition. According to the results of this firing test, Cr plating barrel is superior to standard barrel and nitriding barrel in view of corrosion, wear and maintainability

소구경화기 총열의 크롬도금 손실방지를 위한 질화 영향 사례연구

신재원 ( Shin Jw ),신태성 ( Shin Ts ),최시영 ( Choi Sy ),정상후 ( Chung Sh ),김병규 ( Kim Bk ),권혁린 ( Kwon Hr ) 한국품질경영학회 2017 품질경영학회지 Vol.45 No.3

Purpose: The purpose of this study is to research to protect to loss of chrome-plating of small arms barrel on high temperature in order to extend its life expectency. Methods: The reason why chrome-plating dropped out is main material is weak from heat. Therfore, to make barrel of small arms have higher heat-resistant property, nitriding for barrel before chrome-plating is needed and test of that barrel was handled to improve it. Results: Nitriding before chrome-plating is useful to protect to chrome-plating loss on high temperature. Conclusion: To protect loss of chome-plating of small arms barrel during on firing, pre-nitriding on barrel is effective finally it leads to extend to barrel’s life expectency.

Residual stress analysis of swage autofrettaged gun barrel via finite element method

Mithilesh Kumar Dewangan,S. K. Panigrahi 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.7

Residual stress analysis of swage autofrettaged gun barrel is performed in this study via finite element (FE) method. The swage autofrettagetechnique is one of the modernized pre-stressing methods to enhance the load bearing capacity and fatigue life of all gun barrels. An oversized moving mandrel is forced inside the gun barrel, which deforms the material through physical interference. The process isanalyzed by evaluating residual stresses using a commercially available software package. The deformation effects caused by the mandreland the geometrical variation of the mandrel on the gun barrel are analyzed in this study. This field has been insufficiently researched,but the effect of pre-stressing on the barrel, and at the start and mid-length for the swaging process, is not well examined. Thus, furtheranalysis is required. The variations and effectiveness of the designed pressure band model are shown to define the problem easily. Resultsare evaluated at mid-length using a fixed fringe width percentage (A defined percentage of gun barrel axial length). The desired effectsare well validated through numerical investigation using FE analysis. This study reveals that the geometry should be designed very thoroughlyto determine the after effects. If too many variations occur, then the initial force requirement is extremely high; otherwise, thedesired swaging effect cannot be achieved.

고대 장군의 변천과 사용

신나현(Shin, Na Hyeon) 한국상고사학회 2019 한국상고사학보 Vol.105 No.105

도기장군은 그동안 시대별로 도기를 집성·연구하는 과정에 포함되거나 중·근세 자료에 한정되어 연구가 진행되었다. 그러다보니 장군의 원형인 고대 도기장군에 관한 연구는 거의 이루어지지 못하였다. 이에 남한지역 출토 고대 도기장군을 연구 대상으로 삼고, 시기나 국가·지역별 차이를 파악하기 위한 형식분류를 시도하였다. 그 결과, 고대 도기장군의 변천은 3단계로 구분되었다. Ⅰ단계는 도입기로, 4세기 중후엽부터 5세기 중엽까지로 편년된다. 제작 과정이 복잡한 A형(양측면 둥근형)의 도기장군이 가장 먼저 확인된다. 그 다음 양측면이 대칭을 이루는 A형 도기장군의 특징을 따르되, 제작 과정을 단순화시킨 B형(양측면 편평형)의 도기장군이 등장한다. Ⅱ단계는 성행기로, 5세기 후엽부터 8세기 전엽까지로 편년된다. A형과 B형이 이어지면서 양측면이 대칭을 이루는 특징을 따르지 않고 제작 과정을 단순화시킨 C형(한측면 편평형)의 도기장군이 제작·사용되어 다양한 형태의 도기장군이 공존하게 된다. Ⅲ단계는 쇠퇴기로, 8세기 중엽부터 조선시대 이전까지로 편년된다. 더 이상 A형의 도기장군이 나타나지 않으며 C형의 도기장군만 제작·사용된다. 그리고 국가별로 도기장군의 형태가 구분되는 것을 확인할 수 있었다. 백제 권역에서는 주로 견부와 저부가 원저단경호의 저부와 같이 둥글고동최대경에 비해 경경(脛徑)이 좁은 형태의 도기장군이, 신라·가야 권역에서는 견부와 저부가 원통형을 눕힌 것 같이 직선을 그리고 동최대경에 비해 경경이 넓은 형태의 도기장군이 제작·사용되었다. 한편, 백제에서는 장군의 기원으로 볼 수 있는 견형호(茧形壶)와 같이 일상생활에서 특별한 액체를 저장·운반하는 목적으로 도기장군이 사용된 것으로 추정된다. 반면 신라에서는부장하는 음식을 담는 용기, 즉 제기로 사용된 듯하다. 통일신라시대에 들어서는 고신라의 도기장군과 다르게 일상생활에서 액체를 저장·운반하는 목적으로 도기장군이 사용되었으 며, 크기가 다양해지면서 특별한 액체가 아닌 소변과 장과 같은 다른 액체도 담게 된 것으로 판단된다. The pottery barrel-shaped vessel has been involved in the process of collecting and studying pottery or limited to data from the middle and the modern age. As a result, very little has been done to study the pottery barrel-shaped vessel of ancient, the origin of other materials and age. Thus, the pottery barrel-shaped vessel in ancient was designated as a research target and attempted to classify the types to identify the timing, national and regional differences. As a result, the transition of the pottery barrel-shaped vessel of ancient was divided into three stages. Stage I is an introduction, and the A-type(both sides rounded) is the first to be identified. Then, followed by the B-type(both sides flattened) that simplified the manufacturing process. Stage II is a prevalence, with the A-type and B-type, and the C-type(one-side flattened) being produced and used without conforming to the symmetrical characteristics of both sides, thereby co-existing various types of pottery. Stage Ⅲ is a decline, no more the A-type and only the C-type is produced and used. And we could see that the formats were divided by country and region. In the Baekje region during the Three Kingdoms Period, a rounded shoulder and base, narrow-necked pottery barrel-shaped vessel was created and used. On the other hand, Silla and Gaya region, a flattened sholer and base, broad-necked pottery barrel-shaped vessel was created and used. Meanwhile, in Baekje, a pottery general was used for the purpose of storing and transporting liquids in daily life, such as the Gyeonhyeongho, which can be seen as the origin. while Silla used the container for burial food as sacrificial rites. In the Unified Silla Period, a pottery general was used for the purpose of storing and transporting liquids in daily life, unlike the ancient Silla, and with varying sizes, it was used to contain other fluids such as urine and intestines, not special liquids.

화성 가재리 유적 출토 조선전기 도기장군의 제작기법

송윤정 한국문화유산협회 2012 야외고고학 Vol.0 No.15

장군은 술, 물, 분뇨 등을 저장·운반하는 용기로서 실생활에 요긴하게 사용되어 왔다. 장군은 이와 동일한 용도를 가진 호·옹과는 달리 횡방향으로 누운 긴 동체부에 좁은 구연부가 달리는 형태적 특징을 가진다. 장군이 독특한 형태를 가지는 만큼 그 제 작방법 역시 다른 것으로 알려져 있는데, 호·옹 등의 일반적인 기종이 동체부 상면이 트여 구연부가 되는 것과는 달리 장군은 동체부 양쪽 끝이 완전히 막힌 상태에서 동체 부 일면이 뚫린 다음 구연부가 접합된다. 이와 같은 장군의 제작방법과 관련, 유적에서 출토되는 유물의 관찰을 통한 연구는 아 직까지 부재하다고 볼 수 있다. 본고에서는 이런 점에 착안해서 조선시대 전기의 폐기 시점이 분명한 화성 가재리 유적 가마 출토품을 중심으로 관찰하고 제작기법을 살펴보 았다. 그 결과 화성 가재리 유적 출토 장군에서는 동체부를 제작하는 방법으로 일면폐쇄와 양면폐쇄의 두 가지 방법이 있으며 동체부의 열린면(開口部)를 폐쇄하는 방법으로 원반 폐쇄법과 회전조이기법이 사용됨을 알 수 있었다. 구연부 제작방법으로는 구연부를 별 도로 제작한 후 접합하는 분할성형이 전적으로 행해졌으며 구연부와 동체부를 접합하 는 방법으로는 동체부를 원형으로 도련 낸 후 그 위에 기성형구연부를 접합하는 방법과 동체부를 원형으로 절개한 후 이를 끌어올려 접합하는 방법이 있으며 기성형된 구연부 하단에 트임을 주어 동체부 절개면과 크기를 맞추는 방법이 있음을 알 수 있었다. 아울러 화성 가재리 유적 출토 도기장군에서 도출한 다양한 제작 속성을 토대로 그 제 작과정을 도상으로나마 복원할 수 있었다. The barrel-shaped bottle, which was a container used to store and carry liquid, water or excrement, was useful in everyday life. Unlike the jar and large jar, which also served similar purposes, the barrel-shaped bottle has a unique shape, with a transversely elongated body and a narrow entrance. Due to this peculiar shape, it is believed to have required a different method of production. The barrel-shaped bottle was joined so that the body was completely closed off, and a hole was bored into the body. Studies on the production method of these barrel-shaped bottles have not been carried out thus far. Therefore, in this study, I attempt to describe the production techniques of the barrel-shaped bottles from the site of Gajae-ri, Hwaseong, which dates to the early Joseon period. As a result, it was possible to observe two methods for forming the body of the barrel-shaped bottles from the Gaje-ri site. One method was to close off one side and the other was to close off two sides. Various methods for connecting the bottle entrance and body could also be identified. Based on the various production features that could be observed from actual samples from the Gaje-ri site, it was possible to reconstruct the production process of the barrel-shaped earthenware bottle.

Biased PNG with Maximal-g Barrel-Roll for Survivability Enhancement of Anti-Ship Missiles

Yoon-Hwan Kim,Min-Jea Tahk 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

In this paper, a guidance law for anti-ship missiles to enhance the survivability against ship-borne close-in weapon systems (CIWS) is investigated. As an evasive maneuver of the missile, a barrel-roll maneuver with a time-varying barrel-roll frequency is introduced. The barrel-roll frequency is determined to use all possible energy of the missile. The capturability of the proposed guidance law is proved by using the Lyapunov-like approach. Being compared with the biased PNG with a constant barrel-roll frequency, the proposed guidance law provided better evasion performance against CIWS.

A refinement of the yield surface of a pressure-dependent and elastic-perfectly plastic constitutive model for a particulate compact by considering specimen barreling in triaxial testing

Shin, Hyunho,Kim, Jong-Bong Elsevier 2016 Powder technology Vol.301 No.-

<P><B>Abstract</B></P> <P>The effects of barreling of a particulate compact specimen caused by the end restraint and rubber membrane during a conventional triaxial test on the yield surface of a pressure-dependent and linearly elastic-perfectly plastic constitutive model are investigated via finite element analysis. The combined influence of the end restraint and rubber membrane results in barreling of the specimen which causes artifacts in the experimental deviator stress vs. strain curve determined in the triaxial test. Values of the shear-failure deviator strengths at varying confinement pressures have been modified to exclude the artifact caused by the specimen barreling, followed by the refinement of the yield-surface parameter set of the constitutive model. The refined set predicts the experimental curve better than the unrefined one does.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A linearly elastic-perfectly plastic constitutive model was employed. </LI> <LI> The model was used to simulate a conventional triaxial test. </LI> <LI> The specimen barrels due to the end restraint and rubber membrane. </LI> <LI> The yield surface parameters of the model were refined considering barreling. </LI> <LI> The refined yield surface parameters describe the experiment well. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>