• Title/Summary/Keyword: Heat treatment condition

Search Result 968, Processing Time 0.029 seconds

PWHT Cracking Susceptibility in the Weld Heat-Affected Zone of Reduced Activation Ferritic/Martensitic Steels (핵융합로 구조용 저방사화강의 용접열영향부 후열처리 균열 감수성)

  • Lee, Jinjong;Moon, Joonoh;Lee, Chang-Hoon;Park, Jun-Young;LEE, Tae-Ho;Hong, Hyun-Uk;Cho, Kyung-Mox
    • Journal of Welding and Joining
    • /
    • v.34 no.6
    • /
    • pp.47-54
    • /
    • 2016
  • Post-Weld Heat Treatment (PWHT) cracking susceptibility in the weld heat-affected zone (HAZ) of reduced activation ferritic-martensitic (RAFM) steels was evaluated through stress-rupture tests. 9Cr-1W based alloys including different C, Ta and Ti content were prepared. The coarse grained heat-affected zone (CGHAZ) samples were simulated with welding condition of 30 kJ/cm heat input. CGHAZ samples consisted of martensite matrix. Stress rupture experiments were carried out using a Gleeble simulator at temperatures of $650-750^{\circ}C$ and at stress levels of 125-550 MPa, corresponding to PWHT condition. The results revealed that PWHT cracking resistance was improved by Ti addition, i.e., Ti contributed to the formation of fine and stable MX precipitates and suppression of coarse M23C6 carbides, resulting in improvement of stress rupture ductility. Meanwhile, rupture strength increased with increasing solute C content.

Endoscopic Laser Irradiation Condition of Urethra in Tubular Structure (관형 요도 조직 대상 내시경적 레이저 조사 조건 연구)

  • Hwarang, Shin;Seonghee, Lim;Yeachan, Lee;Hyun Wook, Kang
    • Journal of Biomedical Engineering Research
    • /
    • v.44 no.1
    • /
    • pp.85-91
    • /
    • 2023
  • Stress urinary incontinence (SUI) occurs when abdominal pressure increases, such as sneezing, exercising, and laughing. Surgical and non-surgical treatments are the common methods of SUI treatment; however, the conventional treatments still require continuous and invasive treatment. Laser have been used to treat SUI, but excessive temperature increase often causes thermal burn on urethra tissue. Therefore, the optimal conditions must be considered to minimize the thermal damage for the laser treatment. The current study investigated the feasibility of the laser irradiation condition for SUI treatment using non-ablative 980 nm laser from a safety perspective through numerical simulations. COMSOL Multiphysics was used to analyze the numerical simulation model. The Pennes bioheat equation with the Beer's law was used to confirm spatio-temporal temperature distributions, and Arrhenius equation defined the thermal damage caused by the laser-induced heat. Ex vivo porcine urethral tissue was tested to validate the extent of both temperature distribution and thermal damage. The temperature distribution was symmetrical and uniformly observed in the urethra tissue. A muscle layer had a higher temperature (28.3 ℃) than mucosal (23.4 ℃) and submucosal layers (25.5 ℃). MT staining revealed no heat-induced collagen and muscle damage. Both control and treated groups showed the equivalent thickness and area of the urethral mucosal layer. Therefore, the proposed numerical simulation can predict the appropriate irradiation condition (20 W for 15 s) for the SUI treatment with minimal temperature-induced tissue.

A Study on the Post-Weld Heat Treatment Effect to Mechanical Properties and Hydrogen Embrittlement for Heating Affected Zone of a RE 36 Steel

  • Moon, Kyung-Man;Lee, Myung-Hoon;Kim, Ki-Joon;Kim, Jin-Gyeong;Kim, Seong-Jong
    • Corrosion Science and Technology
    • /
    • v.2 no.6
    • /
    • pp.283-288
    • /
    • 2003
  • The cathodic protection method is being widely used in marine structural steel, however a high tensile steel like RE 36 steel for marine structural steel is easy to get hydrogen embrittlement due to over protection during cathodic protection as well as preferential corrosion of HAZ(Heating Affected Zone) part. In this paper, corrosion resistance and mechanical properties such as elongation and hydrogen embrittlement were investigated with not only in terms of electrochemical view but also SSRT(Slow Strain Rate Test) method with applied constant cathodic potential, analysis of SEM fractography in case of both As-welded and PWHT(Post-Weld Heat Treatment) of $550^{\circ}C$. The best effect for corrosion resistance was apparently indicated at PWHT of $550^{\circ}C$ and elongation was increased with PWHT of $550^{\circ}C$ than that of As-welded condition. On the other hand. Elongation was decreased with applied potential shifting to low potential direction which may be caused by hydrogen embrittlement, however the susceptibility of hydrogen embrittlement was decreased with PWHT of $550^{\circ}C$ than that of As-welded condition and Q.C(quasi cleavage) fracture mode was also observed significantly according to increasing of susceptibility of hydrogen embrittlement. Eventually it is suggested that an optimum cathodic protection potential range not causing hydrogen embrittlernent is from -770 mV(SCE) to -850 mV(SCE) in As-welded condition while is from -770 mV(SCE) to -875 mV(SCE) in PWHT of $550^{\circ}C$.

The Effects of Heat-treating Conditions on Wear Characteristics of High Speed Steel by Powder Metallurgy (분말고속도공구강의 미끄럼 마모특성에 미치는 열처리조건의 영향)

  • Lee, H.Y.;Bae, J.S.;Kim, Y.J.
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.13 no.6
    • /
    • pp.405-411
    • /
    • 2000
  • The effects of added elements, such as Co or Nb, on wear properties of high speed steel by powder metaliurgy(PM-HSS) had been eluminated in auther's previous paper. In addition, it is generally known that the wear properties of materials have been influenced by heat-treating conditions as well. Therefore, a study has been done to clarify the effects of heat-treating conditions on wear properties of PM-HSS. The wear tests have been performed under the same conditions as the previous paper using heat-treated PM-HSS(5%Co-1%Nb) with different quenching and tempering temperatures. The result of this paper shows that wear resistance of PM-HSS is improved with relatively high quenching temperature. However, tempering temperature is not sensitive to the wear resistance in the range of high quenching temperature. It may be deduced by the fact that the shear strength of matrix by strengthening mechanisms due to not only the quenching aging but also dispersion-hardening is improved.

  • PDF

The literatual study on the external medical treatment of Menorrhalgia and Leucorrhea for gynecologic condition (월경통(月經痛) 및 냉대하(冷帶下)에 활용(活用)된 외치법(外治法)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Cho, Sun-Hwa;Jeong, Jin-Hong
    • Journal of Haehwa Medicine
    • /
    • v.9 no.1
    • /
    • pp.319-335
    • /
    • 2000
  • According to the literatual study on the external medical trearment of Menorrhalgia and Leucorrhea for gynecologic condition, the results were as follows. 1. Using external medical treatment for Menorrhalgia is to insert vagina theraphy, fumigation theraphy, to wash vagina theraphy, to insert anus theraphy, to apply hot pack theraphy and use with suppository such as BANSUKHWAN(礬石丸), SASANGZASAN(蛇床子散), KUMBONGHYUNGJU(金鳳衡珠) 2. Using external medical treatment for Leucorrhea is washing and fumigation on vagina, to wash vagina, to insert vagina, cleansing theraphy and use with Suppository such as YONGYEOMGO(龍鹽膏), KAMISASANGJASAN(加味蛇床子散), SASANGSACHUNGSEJE(蛇床子洗劑). 3. ANGELICAE GIGANTIS RADIX (當歸) is in mostly general use for external medical treatment of Menorrhalgia and Leucorrhea, in that order ANSU SEMEN(杏仁), EVODIAE FRUCTUS(吳茱萸), TORILIS FRUCTUS (蛇床子), CORYDALIS TUBER(玄胡索), CINIAMOMI CORTEX(肉桂), CARYOPHYLLI FLOS(丁香), ALUMEN(枯白礬), AQUILARIAE LIGNUM (沈香). 4. The efficacy of medicines to use external medical treatment is as follow to help circulation of blood, to warm spleen and stomach, to warm blood, to warm uterus and remove cold, to remove heat and dry moisture, to down heat-product, to contract bloodvessel, to counteract poison and destory virus, to make energy and blood. 5. KUMBONGHYUNGJU, made same size as cherry and shape vagina medicine, use for Menorrhalgia, menstural irregularity, Leucorrhea, it has the efficacy as follow to remove cold and dry moisture, to warm uterus, to help circulation and romove pain, to down moisture-heat.

  • PDF

Photoluminescence properties of oxy-fluoride glass-ceramics of La2O3-CaF2-Al2O3-SiO2 system (La2O3-CaF2-Al2O3-SiO2 계 oxy-fluoride 결정화 유리의 광 발광 특성)

  • Ha, Taewan;Kang, Seunggu
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.31 no.2
    • /
    • pp.84-88
    • /
    • 2021
  • The change of the photoluminescence properties of La2O3-CaF2-Al2O3-SiO2 glass-ceramics doped with rare earth material, that is used as laser and optical sensors, was analyzed according to heat treatment temperature. The heat treatment conditions for fabricating glass-ceramics were obtained through non-isothermal thermal analysis, and X-ray diffraction analysis was performed to determine the degree of crystal growth and kinds of crystal phases generated according to the heat treatment temperature. Using Scherrer's equation, it was predicted that crystals with a size of 25~40 nm would be generated inside the glass-ceramics. Photoluminescence (PL) analysis showed that the specimens heat-treated at 660℃ to 670℃ for 1 hour had the highest PL intensity. Also, from the CIE color coordinate analysis, all glass-ceramics specimens emitted red-orange light regardless of the heat treatment condition.

A Study of the Medical Records on Metrostaxis(崩漏) of that Made a Profound Study by Yi-Da-Gan(易大艮) and Cold Syndrome with Pesudo-Heat(眞寒假熱) of that Made a Profound Study by Yu-Chang(喩昌) (이대간(易大艮)의 붕루(崩漏) 의안(醫案)과 유창의 진한가열(眞寒假熱) 의안(醫案)에 관한 문헌적(文獻的) 연구(硏究))

  • Kim, Tae-Hee;Han, Kyung-Sook;Park, Young-Bae
    • The Journal of the Society of Korean Medicine Diagnostics
    • /
    • v.9 no.2
    • /
    • pp.1-9
    • /
    • 2005
  • Background: Liu-Yuan-Lei(陸淵雷) said that a medical record is both the marks of treatments and arts made by a excellent practitioner and the essence of TCM(Traditional Chinese Medicine). Jiang-Guan(江瓘) also said that reading medical records is one of the best way to develop one’s abilities If curing a disease without perfect clinical practice. Objectives: study on the special treatment about metrostaxis(崩漏) based on the Yi-Da-Gan(易大艮)’s medical records. and study on the differentiation of abnormal symptoms and signs about cold syndrome with pesudo-heat(眞寒假熱) based on the Yu-Chang(喩昌)'s medical records. Methods: First, read and study the medical records on metrostaxis(崩漏) of that made a profound study by Yi-Da-Gan(易大艮) and cold syndrome with pesudo-heat(眞寒假熱) of that made a profound study by Yu-Chang(喩昌). The next, write a paper on results and conclusions. Results and Conclusions: First, Yi-Da-Gan(易大艮) insist that must control the Qi under the blood disease conditions, taking the case of metrostaxis(崩漏). Secondly, we must study more on estimating the changing condition of Qi and the blood as time goes by, also study on the pulse and pulse condition in the four seasons(四時脈). Thirdly, Yu-Chang(喩昌) insist that be more careful in differentiation of symptoms and signs, taking the case of cold syndrome with pesudo-heat(眞寒假熱). Fourthly, Yu-Chang(喩昌) give an example that in condition of cold syndrome with pesudo-heat(眞寒假熱), sometimes, the pulse and pulse condition can be strong.

  • PDF

Study on Friction Welding of Torsion Bar Material(II) - Effect of PWHT on Friction Weld Quality- (토션바재의 마찰용접에 관한 연구(II) -용접 후열처리가 마찰용접 품질에 미치는 영향-)

  • Oh, Sae-Kyoo;Lee, Jong-Du
    • Journal of Ocean Engineering and Technology
    • /
    • v.4 no.2
    • /
    • pp.94-99
    • /
    • 1990
  • This paper deals with investigating experimentally the effects of PWHT on the weld quality such as strength, toughness, hardness and micro-structure of the welded joints in friction welding of torsion bar material SUP9A bar to bar. The results obtained are summarized as follows; 1) It was certified that the condition of the post-weld heat treatment(PWHT) for the friction welded joints was very satisfactory because both strength and toughness of the joints were improved as almost same as those of the base metal or better by the PWHT. 2) The peak of hardness distribution of the friction welded joints can be eliminated by PWHT, resulting in being almost equalized at the weld interface, the HAZ(heat affected zone) and the base metal. 3) The micro-structure of the base meta., HAZ and weld interface(WI) of friction welded joints welded at the optimum welding condition consists of the same sorbite structure obtained by PWHT and fined sorbite at WI, resulting in increasing toughness as well as strength, and no micro structural defect has been found at the friction welded zone.

  • PDF

Study on Friction Welding of Torsion Bar Material(II) - Effect of PWHT on Friction Weld Quality- (토션바재의 마찰용접에 관한 연구(II) -용접 후열처리가 마찰용접 품질에 미치는 영향-)

  • Oh, Sae-Kyoo;Lee, Jong-Du
    • Journal of Ocean Engineering and Technology
    • /
    • v.4 no.2
    • /
    • pp.244-244
    • /
    • 1990
  • This paper deals with investigating experimentally the effects of PWHT on the weld quality such as strength, toughness, hardness and micro-structure of the welded joints in friction welding of torsion bar material SUP9A bar to bar. The results obtained are summarized as follows; 1) It was certified that the condition of the post-weld heat treatment(PWHT) for the friction welded joints was very satisfactory because both strength and toughness of the joints were improved as almost same as those of the base metal or better by the PWHT. 2) The peak of hardness distribution of the friction welded joints can be eliminated by PWHT, resulting in being almost equalized at the weld interface, the HAZ(heat affected zone) and the base metal. 3) The micro-structure of the base meta., HAZ and weld interface(WI) of friction welded joints welded at the optimum welding condition consists of the same sorbite structure obtained by PWHT and fined sorbite at WI, resulting in increasing toughness as well as strength, and no micro structural defect has been found at the friction welded zone.