電氣化學的 腐蝕 試驗法

백신영 木浦海洋大學校 機關工學部 산업기계시스템연구소 1997 학술대회 논문집 Vol.1 No.1

여러 가지 방법으로 시행하는 부식 시험법 중 전기화학적으로 행하는 부식시험법에 대해 이론, 방법 및 실제 측정 결과를 대비하여 해설하였다. 이들은 어느 측정 장치에 비해도 감도가 높고 순간의 속도를 측정할 수 있으며 여기에다 비교적 짧은 시간에 행할 수 있는 특징이 있다. 뿐만 아니라 정성, 정량적 분석이 가능하며 장시간을 요하는 시험을 아주 단시간에 측정하여 몇백년 후의 부식상태를 예견할 수 있다는 장점이 있다. 그러나 측정하는 전위 또는 전위 값은 시험면 전면의 평균적 정보를 얻기 때문에 국부적인 문제를 놓치는 경우가 있다. 따라서 보통 시험 후 표면의 관찰을 잊지 않을 필요가 있다. 시험법의 방법이 표준화하여 경과의 정확도가 향상되고 점차로 폭넓게 이용될 것을 기대한다.

A Study on the Galvanic Corrosion for Zirconium with Titanium and 316L Stainless Steel

백신영 해양환경안전학회 2013 해양환경안전학회지 Vol.19 No.3

The coastal area of Republic of Korea is very clean compared to other countries. In this reason, west coastal area of our country is a good place for breeding up a fish such as shrimp. In winter season, the heating system is required for preventing shrimp death caused by freezing in the farm. The heater in the heating system for fishery's farm is operated very severe combating corrosion due to high accumulation by feeding material and high temperature in heated sea water. Almost all manufactured heaters of STS 316L and Ti material are scrapped every year due to heavy corrosion such a general and crevice corrosion. For comparing the general and galvanic corrosion in new heater material, the test material of Zirconium (Zr), Titanium (Ti) and STS 316L are tested by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), current density-time methods and microscopic examination in a 3.5% NaCl solution. The corrosion potential (Ecor) measured by potentiodynamic polarization for Zr, Ti and STS 316L reveals -198, -250 and -450mV, corrosion current density 0.5, 2.5 and 6.5㎂/cm^2 respectively. The film resistance measured by EIS are Zr 63,000, Ti 39,700 and 316L 3,150Ω, and the current of Zr-Ti couple is 0.03㎂, whereas Zr-316L SS is 0.1㎂. According to the result of this experiment in 3.5% NaCl solution, Zr is excellent corrosion resistance material than Ti and STS 316L.

산성 용액에서 Ti-6Al-4V재의 전기화학적 부식 거동

백신영 木浦海洋大學校 1997 論文集 Vol.5 No.2

In this paper, the Electrochemical corrosion behavior of Ti-6A1-4V alloys has been studied in an acidic media, and the results are as follows; 1)After completion of potentiodynamic polarozation in 1N H₂SO₄ , HNO₃, and HC1, the measured Ecor were -390.0, +53.0 and -320.0㎷ each, and Ip were 100, 30, and 400 ㎂/㎠, respectively. The Ip 100㎂/㎠ corresponds to 0.33㎜/year in corrosion depth. 2) In completion of Potentiodynamic corrosion test in a 3.5% NaC1 solution for application to sea water and search the effect of ?? to corrosion, Ecor and Ip were measured -298.0㎷ and 2㎂/㎠ each, which indicated that though the presence of ? acclerates corrosion but not so severe than 1N H₂SO₄. 3) Compare Ti-6A1-4V with 316L which developed for usage in high corrosive media, the former exhibited superior corrosion resistant than that of later.

중소형선박 동력전달 추진 축계 수리 및 개발(Ⅰ)

백신영 목포해양대학교 2006 論文集 Vol.14 No.-

현재 중소형선박의 동력전달용 추진축계가 많이 사용되고 있으나 선미관이 통과하는 선미관 패킹부, 베어링이 작용하는 접촉부 등에서 짧으면 1-3년 이내에 마모가 많이 발생하여 축을 사용하지 못하는 경우가 많다. 따라서 이 컨소시엄을 통하여 선박용 기관을 전문으로 연구하는 목포해양대학교의 기술지원을 받아 Cr강재, 304스테인리스강재, 동계합금, 고장력 강재 등에 대하여 재료의 검토, 형상 검토, 성능향상 등의 기술 개발을 하여 축의 절손을 방지 또는 완화 할 수 있는 중소형선박 동력전달 추진 축계를 개발한다. 아울러 축이 마모되면 보수 용접 등에 의한 수리를 하여야 하나 해양수산관련 선박안전법에 따르면 보수용접시 검사를 받도록 되어 있으나 검사 기준이 없어 실시를 못하고 있는 실정이다. 본 컨소시엄을 통하여 재료에 따른 용접 결함 발생 여부, 열처리, 금속조직 및 강도를 측정하여 재생 방법의 기준을 마련하고자 한다. It is very important to develop and repair of propulsion shaft on ship. in addition on this thesis, Inspection of welds and welded assemblies involves knowledge of many factors including dimensional inspection, non-destructive examination methods, welding processes, welding metallurgy, destructive testing, welding process and welder and welding operator performance qualification requirements, and the examination and test requirement by ship's class, standards, and specifications. In this study, the requirement of repair, purpose, present situation, and repair methods have been discussed.

갯벌조업 효율화를 위한 운반기 개발(Ⅱ)

백신영 목포해양대학교 2006 論文集 Vol.14 No.-

산업적으로 국내 갯벌의 자원적 가치는 농지에 비해 10-20배의 가치를 지녔다. 세계적인 갯벌면적으로 캐나다 동부해안, 미국동부해안, 아마존강 유역, 덴마크 -독일-네덜란드 바덴해 등이 있으며, 한국은 갯벌면적이 2,393㎢로 세계 5위에 속하며, 서남해안에 걸쳐 천혜의 자연경관과 더불어 잘 발달된 갯벌습지에서의 자원적 가치는 무한하다고 할 수 있을 것이다. 그러나 최근 무분별한 간척 사업으로 많은 갯벌과 습지가 사라지고 있다. 개발과 보존이라는 차원에서 나머지 갯벌을 최대한 생산성을 최대로 상승 시키고, 생태관광자원화를 해야 할 것이다. 갯벌에서 조업하는 인력 현황은 노령화추세와 부녀자 중심으로 되고 있다. 갯벌에서 작업종사자들이 쉽게 사용하고 운반이나 정비도 간편하게 할 수 있는 갯벌이동수단 즉 갯벌조업 효율화를 위한 운반기 개발을 하여야만 어획작업의 효율화와 노동력향상을 도모 할 수 있을 것이다. 이런 점에 착안하여 갯벌이동장비. 뻘배개량, 꼬막채취기 및 갯뻘 이동용 보트를 개발하였다. It is very important to development of transportation machinery in mud-zone. Although the transportation systems were developed for sea or shore area, such as the water jet, hovercraft etc. they were can't applicable in mud-zone due high viscosity of mud. In this study, the transportation system was developed on the basis of low purchasing cost, easy handling method and high corrosion resistant material. In this study, the details of development for transportation machinery in mud-zone have been reported.

Pourbaix 선도와 전기화학적 분극방법에 의한 304 스테인리스강의 부식거동 연구

백신영 木浦海洋大學校 1997 論文集 Vol.5 No.1

The change of corrosion behavior of 304 stainless steel due to the pH of solution was investigated by experimental work utilizing electro-chemical polarization curves. The experimental results are in agreement with the results predicted by the Pourbaix diagram. The results are : 1) As pH of the solution increases, Ecor increases in the range of pH 0 - 6, and decrease in the range of pH 7 - 14. 2) Ecor is agreed well with predicted by dissolution potential of ?? in the range of pH 0 - 2, ?? and ?? in the range of pH 3 - 9, and ?? in the range of over pH 9. 3) Active and secondary peak can be observed in the pH 0 - 2, and these are disappeared beyond the value of the pH 3. 4) Current density which is proportional to corrosion is linearly proportional to electric potential. 5) For cathodic protection, electric potential of lower than -400mV is required in the whole range of pH values. For higher than pH 3 the rate of corrosion in depth is less than 0.044mm/year without additional corrosion protection treatment.

선박용 재료의 전기화학적 부식에 대한 연구

백신영 木浦海洋大學校 2001 論文集 Vol.9 No.1

Corrosion is defined as 1) the destruction or deterioration of a material because of reaction with its environment, 2) destruction of materials by means of other than straight mechanical, 3) extractive metallurgy in reverse and 4) electrochemical or chemical reaction between a material, usually a metal, and its environment that produce a deterioration of the material and its property. Engineers are consequently responsible for minimizing the costs and risks to the public from corrosion. Most of Ships are operated under sea environment. So ships are situated very corrosive condition. The materials that used in ships are selected and grouped for chemical component. Generally speaking, the most quantity of material that used in the general commercial vessel is steel based materials, for example mild steel, carbon or low alloy steel. The next abundant series is copper, nickel, and titanium based etc. In this study, selected material of Mild steel(RA), stainless steel(SS), high strength brass and titanium are tested corrosion for comparison corrosivity in sea condition. This study will contribute the forecast of corrosion problem of ships and airplanes, electric power generating plants, chemical process and manufacturing plants, concrete structures etc.

유전양극용 Zn의 설계에 관한 연구

백신영 木浦海洋大學校 2000 論文集 Vol.8 No.2

Ships, airplanes, electric power generating plants, chemical process and manufacturing plants, concrete structures, and many others - all are designed, operated, and maintained by under the supervision of engineers. Engineers are consequently responsible for minimizing the costs and risks to the public from corrosion. In this sense, the design for the sacrificial zinc anode is very important for cathodic protection of steel structure such as ship's hull, offshore and oil production structure etc. Corrosion is defined as 1) the destruction or deterioration of a material because of reaction with its environment, 2) destruction of materials by means of other than straight mechanical, 3) extractive metallurgy in reverse and 4) electrochemical or chemical reaction between a material, usually a metal, and its environment that produce a deterioration of the material and its property. In this study, the composition, the size and selection methods for the zinc anode are discussed based on the economic and properties.

용접방법에 따른 AISI 304 및 316L스테인리스강 용접부의 틈부식 거동

백신영 한국마린엔지니어링학회 1991 한국마린엔지니어링학회지 Vol.15 No.4

The crevice corrosion behavior on austenitic AISI 304 and 316L stainless steel welded by TIG, MIG, $CO_2$ and SMA was studied. The results are as follows : In 10% $FeCl_3$ solution and natural sea water sampled near Mokpo port, the base metal of 304 stainless steel showed small amount corrosion, whereas 316L stainless steel did not showed any corrosion in the test periods. The weight loss caused by crevice corrosion increased with increasing weld heat input and residual .delta. ferrite formed in welded part. The corrosion resistance of the welded part was in the order of TIG, MIG, $CO_2$ and SMA. From this tendency, it is proved that the smaller heat input gives the better corrosion resistance.

Ti-6Al-4V재의 전기화학적부식 거동에 미치는 시효열처리의 영향

백신영 한국마린엔지니어링학회 2000 한국마린엔지니어링학회지 Vol.24 No.6

In this paper, the effect of solution and age heat treatment to the corrosion behavior for the Ti-6Al-4V alloy were studied by cyclic polarization methods. Ti-6Al-4V was solution heat treated at $1,066^{\circ}C$ and $966^{\circ}C$ for 5 hours, and followed by age heat treated at $650^{\circ}C$, $600^{\circ}C$ and $550^{\circ}C$ with 1, 2, 4, 8 and 16 hours under vacuum environment. Test solution was 3.5% NaCl with temperature $25^{\circ}C$. The obtained results were as follows: 1. Base metal was exhibited higher electrical charge than that of solution and aged material. With decrease of solution-treatment temperature from 1066 to $966^{\circ}C$, the electrical charge was increased due to softening of micro structure. 2. The corrosion resistance of specimen that solution treated at $966^{\circ}C$ for 5 hours and age heat treated at 650, 660 and $550^{\circ}C$ were increased with increase of aging time to 4, 8 and 16 hours respectively, and then decreased. 3. In case of 316L stainless steel, measured charge and corrosion potential was 0.0627 coulomb and -614 mV respectively. Corrosion resistance of Ti-6Al-4V was higher than that of 316L.