• 한국문화재보존과학회:학술대회논문집
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• 2005.03a
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• pp.163-164
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• 2005

• Journal of Practical Engineering Education
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• v.12 no.1
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• pp.203-212
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• 2020

This study surveyed 244 employees out of a total of 356 graduates from the steel industry in 2015 to February 2019. The employment rate of graduates is POSCO 67.7%, Hyundai Steel 23.8%, POSCO families 13.1%, and Hyundai Steel families 8.5%. The national certificates acquired by each section were surveyed, with 53.1% of metal section, 39.8% of mechanical section, and 7.1% of other section. Preferred national certificates were POSCO, machinery maintenance industry technicians, steelmaking technicians, and Hyundai Steel followed steelmaking technicians, mechanical maintenance industrial technicians. Among other certifications, the national certificate of industrial safety industrial engineer was preferred. In addition, the average number of national certificates per person for major employment is 5.06 for POSCO, 5.35 for POSCO families, 5.29 for Hyundai Steel, and 4.73 for Hyundai Steel families. The average number of national certificates for S-OIL, KEPCO, Poongsan Metal, etc., is 2.51. In conclusion, it was found that the national certificates related to majors are used as the main evaluation data in finding suitable majors and competency for the job when recruiting talents.

• Journal of the Economic Geographical Society of Korea
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• v.7 no.1
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• pp.83-96
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• 2004

Location of firms and construction of new industrial complex generally have an effect on the population change of region. This paper focuses on the population change of Gwangyang city, in particular, the relationship between location of new firm, Gwangyang Works of POSCO, and population change of region. The first construction of Gwangyang Works of POSCO was finished in 1987. The number of population of Gwangyang city increased from 78,478 individuals of 1981 to 138,468 individuals of 2001, and the number of household also increased from 14,917 household of 1981 to 43,176 household of 2001 with the location and construction process of Gwangyang Works of POSCO. The growth of population was greatly revealed during the period of 1987 through 1991 with social increase of pouplation transferred into Gwangyang city from another area. This period related with the completion of Gwangyang Works of POSCO. In addition, population increase was mainly appeared in Eastern Gwangyang area, neighboring area to Gwangyang Works 13,211 peoples of 1981 to 74,956 peoples of 2001. Therefore, it is clear that location of Gwangyang Works of POSCO had a significant impact on the change of population structure and population growth of Gwangyang city since 1981.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.109-116
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• 2021

In order to replace mineral aggregate used as road pavement materials with steel slag aggregate, this present study evaluated mechanical properties of SMA Concrete mixtures using steel slag aggregate as oxidized slag from electric furnace in iron works. The variables of this experiment are the aggregate type of mineral and steel slag and the sieve sized of 10mm and 13mm. The physical properties inclu ding the specific gravity and absorption rate etc. of the slag aggregate mixtu res satisfied the KS standard as asphalt mixtu re. As a resu lt of evalu ating the mechanical properties of the asphalt mixtures, the optimum asphalt content of the slag aggregate mixtures were lower than that of the mineral aggregate mixtures, but other quality standards were all satisfied. In the deformation strength evaluation, the slag aggregate mixtures were measu red slightly higher than that of the mineral aggregate mixtu res, and the dynamic stability test satisfied the 2,000pass/mm standard value in all specimens. And, the moduli of resilient of the slag aggregate mixtures showed an improved value compared with the mineral aggregate mixtures. Therefore, as the resilient rate of the slag aggregate mixtures improved, it is speculated that there will be an effect of improving public performance according to the repeated traffic load of the vehicle.

• Bulletin of the Society of Naval Architects of Korea
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• v.11 no.2
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• pp.53-62
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• 1974

본고(本考)는 포항종합제철(浦項綜合製鐵) 전용항(專用港)의 확장계획(擴張計劃)에 따라서 원료(原料) 운반선(運搬船)의 적정(適正) 크기 및 속도(速度)를 결정(決定)하기 위한 타당성(妥當性) 조사(調査) 연구(硏究)의 예비작업(豫備作業)이다. 먼저 그 기준(基準)으로 소요운임율(所要運賃率)을 택(擇)하여 선박(船舶)의 크기, 속도(速度) 및 상대방(相對方) 원료적출항(原料積出港)에 따라서 수송비(輸送費)를 계산(計算)한 후에 그 결론(決論)으로 선박(船舶)의 대형화(大型化)의 필요성(必要性)을 보였으며, 이 계산결과(計算結果)를 토대(土臺)로 선박(船舶)의 대형화(大型化) 및 효과(效果)를 시설확장(施設擴張)에 투자(投資)되는 자금(資金)을 연차적(年次的)으로 비교(比較)하여 현재(現在) 추진중(推進中)에 있는 포항종합제철(浦項綜合製鐵) 전용항(專用港) 확장계획(擴張計劃)를 검토(檢討)함으로써 선박(船舶)의 적정(適正)크기가 DWT 약(約) 10만(萬) ton임을 보여준다. 또한 제2종합제철(第2綜合製鐵)과의 관계(關係)도 고려(考慮)하여 원료비축기지(原料備蓄基地)와 같은 새로운 시스템에 대한 종합적(綜合的)이고 세밀(細密)한 검토(檢討)의 필요성(必要性)을 보인다.

• Transactions of Materials Processing
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• v.32 no.5
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• pp.287-293
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• 2023

This study aims to develop a computational framework based on the finite element method for modeling the hydrogen embrittlement in martensitic steel. The hydrogen embrittlement is a well-known phenomenon, in which the hydrogen penetrates into the surface, flows through the microstructure and finally leads to pre-mature fracture under external or internal stresses. The current numerical model takes into account the effect of hydrogen on the plasticity and failure behavior of martensitic steel under various stress states. This allows for the construction of a failure criterion that accounts for conventional stress states and hydrogen concentration. The developed model is capable of simulating hydrogen diffusion through the lattice based on the distribution of hydrostatic stress. Additionally, it can calculate the hydrogen concentration in trapped sites, such as dislocations, using a local equilibrium assumption, often referred to as Oriani's equilibrium. The developed model parameters are identified through the tensile tests with and without hydrogen environment, and the performance of model can be validated by analyzing fractured automotive part in the hydrogen environment.

• Journal of the Economic Geographical Society of Korea
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• v.3 no.2
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• pp.63-80
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• 2000

The purpose of this study is to analyze the impact of the Kwang-yang Iron and Steel Co.(KSCO) on the industrialization of the economic structure in Kwang-yang area. The research used the shift-share analysis and regional growth rate differential analysis. KSCO has influenced this area by changing the economic structure from traditional agriculture and fisheries to the manufacturing industry. KSCO also has influenced the population of Kwang-yang area. The number of employees grew from 594 in 1981 to 29,865 in 1992. However, after 1992, employee numbers decreased to 23,399 in 1998. KSCO was constructed in the region of traditional agriculture and fisheries in 1981. The social and economic status of the Kwang-yang area has changed greatly due to the growth of KSCO and the corresponding influx in population. KSCO has developed the related industry and changed this area into a booming industrial city. The number of employee has rapidly increased. At the end of the year 2000, 17,240 people work for KSCO and 39,593(28.7%) of the total population of Kwang-yang are related to KSCO.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.221-224
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• 2002

포항제철소에는 13개의 발전기가 있어 제철소에서 필요로 하는 전력을 자체적으로 945MWH 규모로 공급하고 있다. 발전소에서 사용되는 에너지원은 제철공정에서 부수적으로 발생하는 부생가스(BFG, COG, LDG, CFG)와 외부에서 구매하는 중유, LNG가 있다. 안정적인 전력공급과 비용절감을 위한 발전기 가동계획을 수립하기 위해서는, 조업상황에 따라 변동되는 전력소요량 및 부생가스 발생량을 예측하여 발전기별로 사용될 연료량을 배분하고, 발전기별 효율을 반영한 발전량을 결정하게 된다 이러만 발전기 가동계획 수립을 수작업에 의존하고 있어, 수시로 변화하는 상황에 신속한 대처가 곤란하고, 모든 요소를 고려하기가 어려워 에너지비용을 절감할 수 있는 기회손실의 우려가 있었다. 본 연구에서는 LP 및 NLP를 적응하여 발전기별 연료배분 및 발전량을 결정하는 과정을 자동적으로 수행하는 발전기 가동계획수립 Model을 개발하였다. Data 입·출력용으로 Excel, LP Package는 What's Best, Programming Language는 VBA(Visual Basic for Application)를 활용하였다.

• Journal of Conservation Science
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• v.33 no.6
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• pp.519-532
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• 2017

Studies on ancient ironmaking technologies are primarily based on archaeological surveys and scientific analysis data, and technological systems are examined by comparing the results of restorative experiments. In this study, to examine the ancient iron production technologies such as smelting and smithing in the Jungwon area, a restoration experiment was conducted based on archaeological data, and the iron and slag, etc. produced in the experiment were analyzed. Further, the changes in physicochemical properties due to the smelting of the raw material, specifically, iron ore were determined, and the smithing process, which involves fabrication of ironwares, was analyzed along with the characteristics of each step. In the case of smelting, increasing recovery rates and production of high-quality primary iron material were important for the following processes. For the iron bars produced through the smithing process, it was found that quality improvements made by reducing physical defects such as inclusions or gas holes were more important than the composition of the iron itself. The study also yielded comparative study data for various byproducts, such as smithing slag, which could be utilized in other ironmaking technology studies.

• Journal of Conservation Science
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• v.36 no.2
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• pp.143-151
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• 2020

In the present article, we have analyzed five slags excavated from the Unified Silla period iron smelting site, i.e., location 4-2 of the Inje Bupyeong-ri site, to investigate the iron smelting process. The total Fe content of the slag excavated from the Inje Bupyeong-ri site ranged between 3.65 and 23.78 wt%, lower than that of typical slag, and deoxidation agent of the slag ranged between 65.92 and 88.96 wt%, higher than that of typical slag. These results suggest that the recovery rate of iron was significantly high. Furthermore, cristobalite was detected in most of the samples, and the furnace temperature, estimated by substituting the analyzed data into the FAS and FCS state diagrams, was confirmed as 1,600℃ or more. These results suggest that the operation at the Inje Bupyeong-ri site was performed at a temperature capable of producing cast iron by completely melting the carbon-containing iron. Observation of the microstructure showed that the iron fragments excavated at the Inje Bupyeong-ri site were identified as white cast iron. Steadite from the ternary iron-carbon-phosphorus system was observed in the white cast iron structure. These results show that indirect smelting was performed when the iron smelting by-products were produced. Based on the analysis results, it was confirmed that the Inje Bupyeong-ri site was the indirect smelting site in the Unified Silla period.