• 소성∙가공
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• 제33권3호
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• pp.208-213
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• 2024

Ni-based superalloys have exceptional performance in high-temperature strength, corrosion resistance, etc, and it has been widely used in various applications that require corrosion resistance at high-temperature operations. However, the relatively expensive cost of the Ni-based superalloys is one of the major hurdles. The corrosion-resisted alloy(CRA) clad materials can be a cost-effective solution. In this study, finite element analysis of the hot rolling process for manufacturing of the Alloy 625/API X65 steel CRA clad plates is conducted. The stress-strain curves of the two materials are measured in compressive tests for various temperature and strain rate conditions, using the Gleeble tester. Then, strain hardening behavior is modeled following the modified Johnson-Cook model. Finite element analysis of the hot rolled cladding process is performed using this strain rate and temperature dependent hardening model. Finally, the thickness ratio of the CRA and base material is predicted and compared with experimental values.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.192-199
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• 2006

BIM is a collaborative. model-based way to work. Structural BIM is one of the key elements in the building process where the majority of structural information is created. Open BIM interfaces make it possible for all design information to be produced and managed within a single 3D product model. To make structural BIM a reality between owners, general contractors, architects and engineers. the software used need to be open in their communication. We used to Tekla Structures to provide an open environment through standard interfaces and Tekla Open API collaboration. We have developed MCP(machine cutting plan) and PIM(product information management)to provide cutting plan and drawing and manage to B.O.M, Materials, Production, Shipping and Project.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 추계학술발표대회 개요집
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• pp.191-193
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• 2003

S-N fatigue tests were conducted to investigate the fatigue strength of the small diameter socket and butt welded joints of carbon steels. Experimental parameters were pipe diameter, throat depth, shape of socket welds and welding procedure. Filler metals used in SMAW and GTAW procedure were E9016-G with diameter of 4.0 mm and ER70S-G with diameter of 2.4 m. API 5L Gr.B pipes were adopted as a small diameter branch pipes. All socket fittings were machined from ASTM A105 carbon steel. Fatigue strength in socket weld joints increased with increasing pipe diameter, area of weld metal and weld leg length of pipe side.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1092-1097
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• 2003

S-N fatigue tests were conducted to investigate the fatigue strength of small diameter socket and butt welded joints made of carbon steels. Experimental parameters were pipe diameter, throat depth, shape of socket welds and welding procedure. Filler metals used in SMAW and GTAW procedure were E9016-G with diameter of 4.0 mm and ER70S-G with diameter of 2.4 mm. API 5L Gr.B pipes were adopted as a small diameter branch pipes. All socket fittings were machined from ASTM A105 carbon steel. Tensile strength was not affected by the welding procedure. Fatigue strength in socket weld joints increased with increasing pipe diameter, area of weld metal and weld leg length of pipe side.

• Journal of Electrochemical Science and Technology
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• 제8권2호
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• pp.115-123
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• 2017

Electrochemical noise signals in many cases exhibit a DC drift that should be removed prior to further data analysis. Polynomial fitting and moving average removal method have been used to remove trends of electrochemical noise (EN) in time domain. The corrosion inhibition of synthesized schiff base N,N'-bis(3,5-dihydroxyacetophenone)-2,2-dimethylpropandiimine on API-5L-X70 steel in hydrochloric acid solutions were used to study the effects of drifts removal methods on noise resistance calculation. Also, electrochemical impedance spectroscopy (EIS) was used to study the corrosion inhibition property of the inhibitor. The results showed that for the calculation of $R_n$, both methods were effective in trend removal and the polynomial with m=4 and MAR with p=40 were in agreement.

• Corrosion Science and Technology
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• 제8권4호
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• pp.133-138
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• 2009

For the corrosion protection of the natural gas transmission pipelines, two methods are used, cathodic protection and coating technique. In the case of cathodic protection, defects are embrittled by occurring hydrogen at the crack tip or material surface. It is however very important to evaluate whether cracks in the embrittled area can grow or not, especially in weld metal. In this work, on the basis of elastic plastic fracture mechanics, we performed the CTOD testing with various test conditions, such as testing rate and potential. The CTOD of the base metal and the weld metal showed a strong dependence of the test conditions. The CTOD decreased with decreasing testing rate and with increasing cathodic potential. The morphology of the fracture surface showed the quasi-cleavage at low testing rate and cathodic overprotection. The low CTOD was caused by hydrogen embrittlement at crack tip.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.291-296
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• 2004

The paper describes a test program on welded K-joints fabricated from circular hollow section brace members and chords made with API 2W 50 grade steel produced by POSCO. The K-joints were tested for three loading conditions at RIST. The specimens were tested in reaction frame that allowed vertical uniform loading to the structure. From the test, the crack initiation and development were observed and the fatigue failure could be predicted. The results were also compared with the provided S-N curves by DnV.

• Journal of Welding and Joining
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• 제22권3호
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• pp.50-55
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• 2004

S-N fatigue tests were conducted to investigate the fatigue strength of small diameter socket and butt welded joints made of carbon steels. Experimental parameters were pipe diameter, throat depth, shape of socket welds and welding procedure. Filler metals used in SMAW and GTAW procedure were E9016-G with diameter of 4.0 m and ER70S-G with diameter of 2.4 m. API 5L Gr.B pipes were adopted as a small diameter branch pipes. All socket fittings were machined from ASTM A105 carbon steel. Tensile strength was not affected by the welding procedure. Fatigue strength in socket weld joints increased with increasing pipe diameter, area of weld metal and weld leg length of pipe side.

• 한국정보통신학회논문지
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• 제25권1호
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• pp.115-123
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• 2021

생산관리 시스템은 생산 공정 내의 모든 자원의 공정단위 생산계획을 현장에서 실행하는 것은 물론 생산 관련 품질 데이터까지 다루는 공장정보화시스템이다. 인공지능으로 자동화와 연결성이 극대화되는 4차 산업혁명이 화두가 되면서 제조업체들은 스마트 공장 구축에 관심을 보이나 막대한 구축비와 표준화되지 않은 생산 공정은 스마트 공장구축에 걸림돌이 되고 있다. 그래서 본 논문은 노후화된 공장에서 스마트 공장 구축을 위한 제조관리 시스템을 설계 및 구현한다. 철강 선재 공정을 위한 기초 수준의 스마트 공장을 목표로 Web 기반의 제조공정 시스템을 제안한다. 제안 시스템은 REST API를 사용하여 기존 구축된 ERP 시스템과의 연동을 원활히 지원할 것이며 다양한 기기와 다양한 브라우저에서 사용할 수 있도록 확장성을 고려할 것이다. 제안한 WoT 기반 생산관리시스템을 구현하여 실용성을 보이겠다.

• 한국가스학회지
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• 제17권5호
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• pp.51-57
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• 2013

최근 들어 다양한 재료 및 제조기술의 개발로 가스관 품질이 향상되어 매설심도를 저심도화 할 수 있는 환경이 조성되고 있다. 또한 선진 외국과 비교하여 국내 매설깊이 기준이 약 50cm 정도 깊은 것으로 조사되어 시공비용, 차량지체비용 등을 고려하였을 때 비효율적인 매설깊이 규정인 것으로 판단된다. 따라서 본 연구에서는 매설깊이 변화(0.8m, 1.0m, 1.2m)에 따른 가스관의 응력 및 변형 거동을 분석하였다. 본 연구에서는 수치해석 및 현장시험을 통하여 매설심도 변화에 따른 가스관(API 5L)의 거동특성을 분석하였다. 분석결과, 매설심도의 감소가 가스관의 응력, 변형 특성에 큰 영향을 미치지 않을 것으로 판단되었다.