• Title/Summary/Keyword: Steel manufacture

Search Result 259, Processing Time 0.021 seconds

Manufacturing Technologies and Applications of Steel Strip Products (철강 압연제품의 제조기술 및 응용)

  • 권오준
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 1999.08a
    • /
    • pp.10-21
    • /
    • 1999
  • Recent progress in manufacture of hot and cold rolled steel strip products and their applications were reviewed. The main trend in the technological development has been to meet the customers' requests for quality improvement and cost reduction. The weight reduction to reduce the fuel consumption is the main issue in the automotive industry and, therefore, various steels have been developed to improve formability as well as strength. The steels include super-EDDQ steels, bainitic steels, TRIP steels, etc. In the oil industry, efforts have been focused to improve strength together with either low temperature toughness or HIC/SSCC resistance. The packaging industry is also a highly competitive market, and steel and canmaking companies have worked cooperatively to develop cost-effective canmaking processes as well as high performance steels. This type of cooperation has also been found important in other industries such as the appliance and electronic industries for the benefits of both steelmakers and customers.

  • PDF

The properties of hybrid FRP rebar for concrete structures (콘크리트 보강용 하이브리드 FRP 리바의 특성)

  • 원종필;박찬기;황금식;윤종환
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2003.05a
    • /
    • pp.255-260
    • /
    • 2003
  • The corrosion of steel rebars has been the major cause of the reinforced concrete deterioration. It is FRP rebar that is developed to solve problem of such steel rebar. FRP rebar in concrete structures should be used as a substitute of steel rebars for that cases in which aggressive environment produce high steel corrosion, or lightweight is an important design factor, or transportation cost increase significantly with the weight of the materials. But FRP rebar have only linearly elastic behavior; whereas, steel rebar has linear elastic behavior up to the yield point followed by large plastic deformation and strain hardening. Thus, the current FRP rebars are not suitable concrete reinforcement where a large amount of plastic deformation prior to collapse in required. The main objective of this study was to develop new type of hybrid FRP rebar. The manufacture of the hybrid FRP rebar was achieved pultrusion, braiding and filament winding techniques. Tensile and interlaminar shear test results of hybrid FRP rebar can provide its excellent tensile strength-strain behavior and interlaminar stress-strain behavior.

  • PDF

Fabrication and Mechanical properties of Steel Fiber Reinforced Polyester Resin Composites Utilizing by-Products (Fly Ash) (산업부산물을 이용한 강섬유보강 폴리에스터 수지복합체의 제조 및 역학적 특성)

  • 박승범;윤의식
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1992.04a
    • /
    • pp.35-40
    • /
    • 1992
  • Results of an experimental study on the manufacture, the workability and mechanical properties of steel fiber reinforced polyester resin composites utilizing industrial waste products are presented in this paper. The fly ash polyester resin composites using steel fiber, fly ash and calcium carbonic acid (CaCo3), unsaturated polyester resin, styrene monomer, cobalt octate and methyl ethyl ketone peroxide, fine and coarse aggregates are prepared with various filler~binder rations, binder rates and mixing conditions. As a test results, the workability of steel fiber reinforced polyester resin composites are considerably dropped with increasing fly ash-binder ratio and steel fiber volume. And compressive, flexural strength and bending toughness of the composites are remarkably improved with augmenting fiber contents.

  • PDF

Mold Design for Large STS Ingot (대형 STS 잉곳 주조용 몰드 설계 기술)

  • Oh, S.H.;NamKung, J.;Kim, N.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2008.05a
    • /
    • pp.43-45
    • /
    • 2008
  • According to industrial development, Ingots are more large and various. In particular large STS ingot. The probability of shrinkage cavity occurrence is higher than carbon steel and alloy steel. To manufacture ultra clean steel the technical development is nearly necessary for example controlling inclusions and total [H]. In this study, after measured the mold temperature and adjusted thermo conductivity of STS steel and compared existing mold to new one with CAE. As a result, the new mold more reduced than existing mold for the probability of shrinkage cavity occurrence.

  • PDF

Behaviors According to the Reinforcing Method of the Support Diaphragm Manhole in Steel Box Girder Bridge (강박스거더 지점부 다이아프램 맨홀의 보강방법에 따른 거동)

  • Lee, Seong Haeng;Kim, Kyoung Nam;Jung, Kyoung Sup
    • Journal of Korean Society of Steel Construction
    • /
    • v.17 no.6 s.79
    • /
    • pp.649-660
    • /
    • 2005
  • Since the diaphragm manhole of steel box girder bridges is designed generally from experience, it has become the primary factor in the excessive cost of steel bridge construction. For the economical and efficient manufacture of diaphragm manholes, it is necessary to study the exact behavior of the diaphragm manhole in a steel box girder bridge. In this study, both an experimental test and a structural analysis are performed to verify the behavior of the diaphragm manhole in a steel box girder bridge. A detailed structural analysis was performed according to various diaphragm manhole shapes, and in conclusion, the suitable reinforcement method for the support of diaphragm manholes in steel box bridges is presented.

A Survey on the Status of Noisy Working Environment in Manufacturing Industries (제조업 산업장의 소음 작업환경 실태에 관한 조사 연구)

  • Kim, Joon-Youn;Kim, Byung-Soo;Lee, Chae-Un;Jun, Jin-Ho;Lee, Jong-Tae;Kim, Jin-Ok
    • Journal of Preventive Medicine and Public Health
    • /
    • v.19 no.1 s.19
    • /
    • pp.16-30
    • /
    • 1986
  • In order to prepare the fundamental data for the improvement of noisy working environments and the effective hearing conservation program on workers exposed to industrial noise, the authors surveyed the working processes and evaluated the noise levels on 56 manufacturing industries in Pusan area from April to July in 1985. The results were summarized as follows : 1. The noise level was the highest in shipbuilding and repairing(95.6 dBA), and followed by steel rolling(94.0 dBA), manufacture of motor vehicles(93.1 dBA), manufacture of fishing nets(92.9 dBA), manufacture of testiles(92.5 dBA), iron and steel foundries(89.3 dBA), manufacture of metal products(89.1 dBA), preserving and processing of marine foods(87.0 dBA), manufacture of rubber products(85.3 dBA), manufacture of plywood(84.9 dBA) and manufacture of paints(84.5 dBA). 2. Among fifty surveyed working processes, the noise level of twenty-one processes (42%) exceeded the threshold limit value for 8 hours per day. 3. As the allowable exposure times by governmental threshold limit values to industrial noise level(dBA), cocking of shipbuilding and repairing and plating(CGL) of steel rolling were the shortest(30 minutes), and followed by assembling(rivet) of manufacture of motor vehicles(1 hour) weaving of manufacture of textiles and shot, machine, pipe laying of shipbuilding and repairing(2 hours). 4. By the result of octave band analysis on noisy working processes in excess of 90 dBA, the sound level was the highest at 2,000 Hz or 4,000 Hz. 5. It was recognized that the measurement of overall sound pressure level was also effective as octave band analysis in evaluating the industrial noise.

  • PDF

Development of Multi-layer Bellows using Ferritic Stainless Steel (페라이트계 스테인리스강을 사용한 다층형 벨로우즈 개발)

  • Suh, C.H.;Oh, S.K.;Jung, Y.C.;Choi, J.Y.;Park, M.K.;Kim, Y.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2008.10a
    • /
    • pp.281-285
    • /
    • 2008
  • Ferritic stainless steel is used for parts of exhaust system of commercial vehicle, because it has such advantages as low price and high corrosion resistant compared with austenite stainless steel. Even though ferritic stainless steel has these merits, to manufacture multi-layer bellows with complex geometry, austenite stainless steel is being used in the industry, because of it's high ductility. However, recently, the mechanical property of the ferritic stainless is getting improved and alternating austenitic stainless steel. In this paper, the possibility of mass production of bellows made of ferritic stainless steel like MH1 and 443CT is studied. Tensile test and ridging test are carried out to observe mechanical properties of STS304, MH1 and 443CT. Forming analysis using FEM is performed to investigate plastic strain during forming process. Prototype bellows has been made using STS304, MH1 and 443CT, respectively, and fatigue tests are carried out to evaluate fatigue life of bellows.

  • PDF

Case Analysis of Risk Assessment for Steel and Iron Works (제철 사업장 위험성평가 사례 분석)

  • Hong, Sung-Man;Park, Peom;Kim, Kwang-Hyoun
    • Journal of the Korea Safety Management & Science
    • /
    • v.12 no.1
    • /
    • pp.11-18
    • /
    • 2010
  • In the steel industry, steel is manufactured and processed to produce a variety of steel products. The industry provides fundamental materials to the whole range of industries including car, ship, electric appliance and construction industries, so that it is very important as an infrastructure industry. The steel manufacture process involves aerial work, many danger factors caused by the treatment with hazardous gases including BFG and COG and by high pressure gases including $H_2$, $O_2$, $N_2$ and LPG. It requires the management over the large area because many workers work in a plant. The potential dangers in the steel plant were identified and the effect of the danger assessment was verified through the analysis of the danger assessment for the steel plant. The allowed degree of danger was lowered after the improvement through the danger assessment in the plant where the case studies were conducted, which indicates that the danger assessment is highly effective.

The Properties of Fluidity and Compressive Strength of Unsaturated Polyester Polymer Concrete According to Replacement Ratio of Rapidly-Chilled Steel Slag Fine aggregate (급냉 제강 슬래그 잔골재 대체율에 따른 불포화 폴리에스테르 폴리머 콘크리트의 유동성 및 압축강도 특성)

  • Kim, Jae-Won;Seo, Jung-Pil;Sun, Joung-Soo;Chi, Duck-Jin;Hwang, Eui-Hwan;Kim, Jin-Man
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2007.04a
    • /
    • pp.43-46
    • /
    • 2007
  • This study dealt with the influence of the replacement ratio of rapidly-chilled steel slag on fluidity and compressive strength of unsaturated polyester polymer concretes. The rapidly-chilled steel slag used in this study, a by-product which is produced by refining pig iron during the manufacture of steel, was controled by a air-jet method which rapidly cools substance melted at a high temperature. Experimental results show that fluidity and compressive strength of unsaturated polyester polymer concretes increase with increasing replacement ratio of rapidly-chilled steel slag. Use of rapidly-chilled steel slag was found to be effective for improving fluidity and compressive strength of rapidly-chilled steel slag.

  • PDF

Study on the Effect of Induction Heating with Alloying Elements for the Pre-Heat Treated Steel of 100kgf/$mm^2$ Tensile Strength (100Kgf/$mm^2$급 선조질강의 합금원소에 따른 유도가열효과에 관한 연구)

  • Park, J.T.;Ahn, S.T.;Kwon, D.H.;Seo, J.H.;Kang, N.H.;Youn, D.J.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2009.05a
    • /
    • pp.40-43
    • /
    • 2009
  • This study is for investigating the effect of induction heating with various alloy elements to manufacture the pre-heat treated steels of 100kgf/$mm^2$ for cold heading. For four kinds of steels, the condition of induction heating (especially, induction tempering) were observed, and their microstructure and tensile and compressive properties were investigated. The middle carbon steel and the low carbon Cr-Mo steel are needed the higher Grange-Baughman tempering parameter than that of the low carbon Cr steel to obtain 100kgf/$mm^2$ tensile strength. For accomplishing the pre-heat treated steel of 100kgf/$mm^2$ tensile strength having advanced cold heading. It is needed that the pre-heat treated steel is manufactured by induction quenching and tempering with the low carbon alloy steel to have the high ratio of ferrite and the fine globular cementite simultaneously.

  • PDF