• Title/Summary/Keyword: tensile strength and elongation

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The tensile characteristics of steel sheets at warm condition (박판의 온간상태에서의 인장특성)

  • 최치수
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03a
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    • pp.49-52
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    • 1999
  • In the present study the tensile test was carried out for steel sheets to offer the database for the material characteristics at various temperature condition. The results are constructed with tensile strength total elongation Lankford vale and the flow curve and these can be employed usefully into the analyzing program as input data for the sheet metal forming processes at warm condition.

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Effect of Deformation Temperature, Strain Rate and Grain Size on the Tensile Properties of 304L Stainless Steel (304L stainless Steel의 인장성질에 대한 변형온도, 변형속도 및 결정입도의 영향)

  • Kang, C.Y.;Sung, J.H.
    • Journal of the Korean Society for Heat Treatment
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    • v.3 no.2
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    • pp.20-31
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    • 1990
  • This investigation has been carried out to make clear the effect of deformation temperature, strain rate and grain size on the tensile properties of 304L stainless steel. Tensile properties of the metastable austenitic 304L steel remarkably influenced by deformation temperature. Tensile strength increased with decreasing deformation temperature and the elongation showed maximum value near $40^{\circ}C$. In order to obtain the high elongation, a large amount of deformation is available in austenite before martensitic transformation and the martensite has to be induced gradually. Tensile strength and elongation increased with decreasing grain size. The temperature representing the maximum elongation shifted to low temperature and the peak width of elongation became broaden with decreasing austenite grain size. The volume fraction of strain induced martensite decreased with decreasing austenite grain size. As the strain rate increase, the temperature representing the maximum elongation value shifted to high temperature and volume fraction of strain induced martensite decreased.

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Reological Studies on Cocoon Filament II. Changes of strength and elongation at breaking related to the stretching speed and swelling degree (견사의 탄성적성질에 관한 연구 II. 인장속도 및 팽윤에 따른 파괴강신도의 변화)

  • 남중희
    • Journal of Sericultural and Entomological Science
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    • v.14 no.2
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    • pp.105-112
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    • 1972
  • The effects of the stretching speed and the swelling degree of cocoon filaments on load-elongation curve were tested by tensilon with special attachments. The values of breaking strength, elongation at break and initial tensile strength obtained from load elongation curves are summarized as follows; 1. The breaking strength of the swollen cocoon filament appeared to increase at the high stretching speed, while elongation at break decreased. 2. Load-elongation curve became crinkled at the low speed of stretching. It suggests that both slip and break of the macrofibrils may occur in swelling of cocoon bave. 3. Breaking strength appeared to considerably decrease and elongation at break not to increase in swelling test at 9$0^{\circ}C$ for 60 min. 4. The initial tensile strength was influenced by the stretching speed and swelling degree of cocoon filaments.

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Correlationship between Tensile Properties and Damping Capacity of 316 L Stainless Steel (316 L 스테인리스강의 인장성질과 감쇠능의 관계)

  • Kwoon, Min-Gi;Kang, Chang-Yong
    • Korean Journal of Materials Research
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    • v.24 no.1
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    • pp.1-5
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    • 2014
  • This study is experimentally investigated whether or not a relationship exists between the mechanical properties and damping capacity of cold-rolled 316 L stainless steel. Deformation-induced martensite was formed with surface relief and directionality. With the increasing degree of deformation, the volume fraction of ${\varepsilon}$-martensite increased, and then decreased, while ${\alpha}^{\prime}$-martensite increased rapidly. With an increasing degree of deformation, tensile strength was increased, and elongation was decreased; however, damping capacity was increased, and then decreased. Tensile strength and elongation were affected in the ${\alpha}^{\prime}$-martensite; hence, damping capacity was influenced greatly by ${\varepsilon}$-martensite. Thus, there was no proportional relationship between strength, elongation, and damping capacity.

Effects of Strain Rate and Temperature on Tensile Properties of High Mn Twinning Induced Plasticity Steels (고망간 Twinning Induced Plasticity 강의 인장 특성에 미치는 변형률 속도와 온도의 영향)

  • Lee, Junghoon;Lee, Sunghak;Shin, Sang Yong
    • Korean Journal of Materials Research
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    • v.27 no.12
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    • pp.643-651
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    • 2017
  • Four types of high Mn TWIP(Twinning Induced Plasticity) steels were fabricated by varying the Mn and Al content, and the tensile properties were measured at various strain rates and temperatures. An examination of the tensile properties at room temperature revealed an increase in strength with increasing strain rate because mobile dislocations interacted rapidly with the dislocations in localized regions, whereas elongation and the number of serrations decreased. The strength decreased with increasing temperature, whereas the elongation increased. A martensitic transformation occurred in the 18Mn, 22Mn and 18Mn1.6Al steels tested at $-196^{\circ}C$ due to a decrease in the stacking fault energies with decreasing temperature. An examination of the tensile properties at $-196^{\circ}C$ showed that the strength of the non-Al added high Mn TWIP steels was high, whereas the elongation was low because of the martensitic transformation and brittle fracture mode. Although a martensitic transformation did not occur in the 18Mn1.9Al steel, the strength increased with decreasing temperature because many twins formed in the early stages of the tensile test and interacted rapidly with the dislocations.

The Mechanical Appearances and Microscopic Tissue Reactions of the Suture Materials in vivo (생체내 이식된 흡수성 봉합사들의 물리적 성질 변화와 조직 소견에 관한 연구)

  • 김남중;김명철
    • Journal of Veterinary Clinics
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    • v.13 no.2
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    • pp.184-194
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    • 1996
  • A comparative study of three absorbable suture materials of chromic catgut, Dexon II (a polyglycolic acid suture with a polycaprolate coating system) and Coated Vicryl (a polyglactin 910 suture with a glycolide-lactide-calcium stearate coating system) was undertaken in terms of tensile strength, breaking elongation, appearances of the suture materials in the subcutaneous layer of rats and of tissue reaction in the intramuscular layer of rats. The initial tensile strength of chromic catgut and the tensile strength after 21 days were about 1.55 kg and 0.19 kg, respectively. Those of Dexon II were about 2.01 kg and 0. 20 kg, respectively. Those of Coated Vicryl were about 2.39 kg and 0.48 kg, respectively. Coated Vicryl showed the highest tensile strength among the three materials during the whole period. On the other hand, Dexon II showed the highest breaking elongation among the three materials during the first week. But the breaking elongation of Dexon II rapidly continuously decreased during the whole period. The appearances of the suture materials in the subcutaneous layer of rats showed that chromic catgut was the fastest among the three materials, whereas it formed comparatively much connective tissue. The intramuscular absorption rate and tissue reaction of Dexon II were similar to those of Coated Vicryl. The intramuscular absorption rate of these was fairly late when compared with chromic catgut. And the tissue reaction appearance of these showed the formation of a granuloma with foreign body giant cells, macrothages and epitheloid cells by the 28th day in the experimental period.

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The Tensile Characteristics of Steel Sheets at Various Temperature Conditions (박강판의 온도변화에 따른 인장특성)

  • 이항수;오영근
    • Transactions of Materials Processing
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    • v.10 no.2
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    • pp.101-110
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    • 2001
  • The thermal problem of press work is classified into two cases. First, the temperature of forming die passively rises due to the heating effect of plastic deformation. The warm forming is the second case in which the external heating is applied to the die and blank holder. So, the purpose of this study is to provide database for the forming characteristics at various temperature conditions. In this study, the tensile test was carried out for the commercial steel sheets such as SCPI and SCP3C with the thickness of 0.7mm and 1.4mm respectively. The tensile strength, total elongation, Lankford value and the flow curve have been obtained at the temperature of $25^{\circ}C$, $50^{\circ}C$, $100^{\circ}C$, $150^{\circ}C$, $200^{\circ}C$, $250^{\circ}C$ and $300^{\circ}C$, respectively. From the results, we can see that both the tensile strength and total elongation decrease as the temperature increases. In the light of anisotropy, the effect of thickness is dominant than the material specs. For the temperature dependency of flow curves, there are only small differences for the work-hardening exponent, and the strength intensity decreases monotonically as temperature increases. The present results we useful as input data for the analysis of sheet metal forming processes with the various temperature conditions.

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Comparison Study of Physical Properties between Two Silicone Gel Sheets (새로 개발한 실리콘젤시트의 물성에 대한 연구)

  • Yun, Young Mook;Kang, Nak Heon;Kim, Tae Joon
    • Archives of Plastic Surgery
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    • v.35 no.6
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    • pp.659-662
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    • 2008
  • Purpose: Silicone gel sheet(SGS) is used for preventing and treating keloid or hypertrophic scars. Because the product is weak in tear strength and adherence, it requires several replacements, which requires high cost. As a solution for this problem, we developed a new silicone gel sheet, named as Scar Clinic, and confirmed its physical properties. Methods: Tensile strength, elongation rate, adhesiveness, and water vapor transmission rate were experimentally compared between the most commonly used SGS product and the Scar Clinic. Results: The newly developed SGS showed better results compared to the existed SGS in regards to tensile strength, elongation rate, adhesiveness, and water vapor transmission rate. Conclusion: The Scar Clinic showed higher durability and flexibility. It will be a useful product for treating scars clinically.

A Study on the Properties and Utilization of Chitosan Coating 1. Affecting Factors on the Rheological Properties of Chitosan Film as a Coating Agent (게껍질에서 추출한 chitosan 필름의 이용에 관한 연구 1. 도포재로써의 chitosan 물성에 영향을 미치는 인자)

  • SON Byung-Yil;PARK Seong-Min;KIM Hyonng-Seub;LEE Keun-Tai
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.4
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    • pp.395-398
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    • 1999
  • Chitin was isolated from red snow crab (Chinonecetes japonicus) and deacetylated by boiling alkaline solution to produce chitosan. The physical properties of chitosan solution and its film properties was examined, As the molecular weights of chitosan was increased from 297Kpa to 319Kpa, the tensile strength, degree of elongation and water permeability of chitosan film were increased. As the degree of deacetylation of chitosan was increased, the tensile strength, the degree of elongation and water permeability of chitosan film were increased. As the concentration of chitosan solution was increased, the degree of elongation and water permeability of film were increased, whereas the tensile strength of film was decreased, As the pH of chitosan solution was increased, the tensile strength and water permeability of film were decreased, whereas the degree of elongation of film was increased.

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A Study on the Retained Austenite and Tensile Properties of TRIP Type High Strength Steel Sheet with Cu (Cu 함유 TRIP형 고장력 강판의 잔류오스테나이트 및 인장특성에 관한 연구)

  • Kang, C.Y.;Kim, H.J.;Kim, H.G.;Sung, J.H.;Moon, W.J.
    • Journal of the Korean Society for Heat Treatment
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    • v.12 no.3
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    • pp.231-239
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    • 1999
  • Volume fraction and morphology of retained austenite, tensile properties of TRIP type high strength steel sheet with Fe-C-Si-Mn-Cu chemical composition have been investigated. The retained austenite of granular, bar and film type existing in specimen was obtained after intercritical annealing and austempering. The granular type retained austenite increased with increase of intercritical annealing and austempering temperature. With increase of intercritical annealing temperature, retained austenite and carbon contents increased. Maximum contents of retained austenite was obtained by austempering at $400^{\circ}C$. The maximum tensile strength was obtained by austempering at $450^{\circ}C$ and maximum elongation was obtained at $400^{\circ}C$. T.S${\times}$E.L value increased with increase of retained austenite contents due to the elongation strongly controlled by contents of retained austenite, but tensile strength was affected with various factors such as bainitic structure etc.

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