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.

박용기관의 Nox 생성과 De-NOx에 대한 고찰

백신영 木浦海洋大學校 1999 論文集 Vol.7 No.2

New Annex VI to MARPOL 73/78 and IMO NOx Technical Code were adopted by the IMO in september 1997. According to regulation 13 Nox of the annex VI. this regulation shall apply to: 1) Each diesel engine with a power output of more than 130kw which is installed on a ship constructed on or after 1 Jan. 2000: and 2) Each diesel engine with a power output of more than 130kw which undergoes a major conversion on or after 1 Jan. 2000. While the requirements of the regulation could not be enforced before the entry force of the annex VI, each engine which will become retrospectively, subject to the provisions of the Regulation 13 upon its entry force, should be certified in accordance with the requirements of the Technical Code as mentioned in IMO MPEC Circular letter. Considering international status of out country as leader at a shipbuilding and ship owning in the world, controlling of emission of air pollutants from marine diesel engines became more and more important issue to us in a recent days. Implementation of immediate pollutants emission control regulation, standardization of test and certification procedure are required to reduce air pollution by marine engines.

갯벌조업 효율화를 위한 운반기 개발(Ⅰ)

백신영,안병원,김도희 木浦海洋大學校 2005 論文集 Vol.13 No.-

육상이나 수상과는 달리 이질 함량이 높은 갯벌이나 늪지에서의 이동수단으로는 항공엔진이나, 프로펠러구동에 의한 호퍼크래프트가 있으나, 고가의 장비이며 조작이 곤란하고 어촌에서 조업하는 사람이 고령화 추세와 부녀자중심으로 되어 있을 뿐 아니라 젊은 사람들이 계속 도시로 유출되고 있어 실제 작업 노동력이 감소되고 있는 추세에서 갯벌작업에서의 운반기로 도입하는 것은 부적절하다. 따라서 효율적인 주행 조건에 맞는 추진체 채택을 위한 국내갯벌의 생태물리학적 지도를 조사 작성하고 현지 조업현장의 설문조사를 통해 각 지역별 갯벌 어획물에 적합한 갯벌운반기와 관련어구 최적설계와, 부녀자 중심 갯벌어업종사자와 평균연령 60대를 감안한 이동과 조작이 간편하며 기동성이 좋은 운반기 및 조업시 밀물 실종사고가 잦은 점과 해풍, 해수에 노출되는 점을 감안한 기동성과 내구성을 지닌 운반기 개발에 대하여 연구하였다. 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.

Austenite Stainless Steel 熔接部의 凝固形態와 殘留 Ferrite 에 대하여

白新榮 木浦海洋大學校 1995 論文集 Vol.3 No.1

In this study, the morphology of solidification and amount of retained Ferrite on the welded austenitic stainless steel has been studied, and the obtained result are as follows: 1. The morphology of solidification are divided Austenite. Austenite-Ferrite. Ferrite-Austenite, and Ferrite. In case of 304 SS, the primary solidified phase is Ferrite, where as in case of 316L. Austenite phase is solidified first. 2. The structure of solidified section on the 304 and 316L stainless steel is Cell and dendrite types. Their growth direction is parallel to the weld pool. 3. The amount of retained Ferrite on the welded section is higher than that of predicted by Delong and Scheffler.

오스테나이트 스테인리스강 용접부의 응력부식 거동에 미치는 용접 방법의 영향

백신영 한국마린엔지니어링학회 1995 한국마린엔지니어링학회지 Vol.19 No.4

To study the effect of welding methods on the Stress Corrosion Cracking (SCC) behavior of welded AISI type 316L and 304 austenitic stainless steel, the Slow Strain Rate Technique(SSRT) has been adopted in the boiling 45 wt% $MgCl_2$ solution. The results are as follows. 1) Welded sections are more susceptible than base metal in SCC, and the rank of SCC, and the rasistance in welding method is TIG, MIG, $CO_2$ and ARC. 2) The Ultimate tensile strength(UTS) and the strain of both base metal and welded joint are reduced as decreasing extension rate. 3) The SCC resistance of 316L base metal and welded sections are superior than that of 304. 4) The tendency of pitting and the SCC suseptibility are agreed well, and the SCC site is welded deposit section in 316L whereas HAZ in 304.

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.

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.

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.

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.