• 한국재료학회지
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• 제21권6호
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• pp.303-308
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• 2011

The effect of heat treatment on the micro-structures and the mechanical properties of 0.002% boron added low carbon steel was investigated. The tensile strength reached the peak at about $880-890^{\circ}C$ with the rising quenching temperature and then the hardness decreased sharply, but the tensile strength hardly decreased. The tensile and yield strength decreased and the total elongation increased with a rising tempering temperature, but the tensile and yield strength sharply fell and the total elongation prominently increased from above a $400-450^{\circ}C$ tempering temperature. Tempered martensite embrittlement (TME) was observed at tempering condition of $350-400^{\circ}C$. In the condition of quenching at $890^{\circ}C$ and tempering at $350^{\circ}C$, the boron precipitates were observed as Fe-C-B and BN together. The hardness decreased in proportion to the tempering temperature untill $350^{\circ}C$ and dropped sharply above $400^{\circ}C$ regardless of the quenching temperature.

• 열처리공학회지
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• 제22권4호
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• pp.210-216
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• 2009

Stainless steel EGR cooler of diesel engine is widely used to prevent the corrosion due to the content of sulfur in diesel fuel. The strength of brazed joint between stainless steel materials is very important. It is essential to observe the spreading ratio of the filler metals under the condition of deoxidation or vacuum during heating process. In this experiment, spreading ratio was tested to find the optimum brazing condition for stainless steel using brazing filler metals of FP-613, BNi-2 and BNi-5 on sus304 and sus410. Anti-corrosion tests were also performed on the above filler metals with solution of 5% $H_2SO_4$, 65% $HNO_3$ and 5% $NH_4OH$. Consequently FP-613 has good ability for anti-corrosion with 30% of chromium content compared with other filler metals. The optimum brazing conditions are occurred at $960^{\circ}C$ for 90 min. and at $1090^{\circ}C$ for 50 min. at the same degree of vacuum, $2{\sim}3{\times}10^{-3}$ Torr.

• 대한한의학원전학회지
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• 제33권1호
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• pp.135-147
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• 2020

Objectives : This study focuses on the condition Yinynagjiao, which was first mentioned in 『Huangdineijing』, on the cause, mechanism and reason for it being described as fatal. Later doctors's understanding and treatment of this condition were examined subsequently. Methods : Verses related to Yinyangjiao from texts such as 『Huangdineijing』, 『Jinkuiyuhanjing』, 『Maijing』 were cross-examined focusing on their context and difference in expression with reference to annotations and later texts that mention Yinyangjiao. Based on the findings, its mechanism and treatment methods as found in Wenbing texts were compared with descriptions from previous texts. Results & Conclusions : According to 『Huangdineijing』, heat disease belongs to the Shanghan category, treated through promoting perspiration. In the confrontational position between JingQi and XieQi, perspiration could be understood as the result of JingQi's victory that lead to the discharge of XieQi in the form of sweat. Yinyangjiao is the opposite situation where Jing is discharged while heat toxin sinks into the body, thus being fatal, and treatment aimed for perspiration not adequately addressing the main problem which was ultimately expected to resolve through means of solid Yin Jing that would stabilize the pulse in due time. On the other hand, Wenbing scholars saw the pathogen as heat, shifting previous perspectives entirely. As a result, instead of applying pungent/warm medicinals to promote sweating, they suggested the use of cool, sweet/moist medicinals to cool the heat and nourish Yin as means of treating the condition.

• 열처리공학회지
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• 제27권2호
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• pp.65-71
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• 2014

SMF9060 material is a Fe-based powder sintered alloy that is used for several automobile components such as Synchronize Hub, oil pump and transmission. These components are required excellent wear resistance and durability. In this study, we have performed a dry wear test at the ambient air and Ar gas conditions in the room temperature, and a lubricant wear test at the room temperature and engine oil temperature of $100^{\circ}C$. The amount of wear volume and coefficient friction are measured by a Profilometer and a Ball on disk type wear tester. The wear volume in Ar gas condition was a little higher than that in the ambient air condition. However the wear volume in the lubricant wear condition was much lower than in the dry wear condition. XRD analysis of the debris in Ar gas condition showed that the oxide film was not formed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.113-116
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• 1995

In this experimental study,aluminum hotforging was conduct to get superior pistion to cast piston. Cast structure of billet is destroyed, harmful defects is removed by forging process. We proposed the direction od die design by observing formability of product according to die shape. The microstructure of forged products with different preform was investigated to determine inital billet shape. We proposed appropriate heat treatment condition for improvement of mechanical properties.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 1999년도 제1회 학술대회논문집(KIASC 1st conference 99)
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• pp.14-17
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• 1999

Four designed $Nb_{3}$Sn superconductors have been fabricated in order to investigate the effect of pre-heat treatment for internal tin process. 3 types of sub-elements and 2 types of Sn reservers were fabricated. Diffusion of Sn is better in the strand divided Sn equally than in the strand had one large Sn reserver during pre heat-treatment.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.332-333
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• 2007

The effect of asymmetric rolling on the recrystallization texture of an AA 3003 Aluminum alloy was investigated by X-ray diffraction. It was found that the texture of asymmetrically rolled sheets prior to subsequent heat treatment promoted the formation of the <111>//ND textures, and remained after heat treatment at $275^{\circ}C$ during 20 min in salt bath condition.

• 열처리공학회지
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• 제22권4호
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• pp.203-209
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• 2009

Dual mass flywheel is the newly developed flywheel system which reduces the noise and vibration and make a better and comfortable ride of cars by adding inertia mass and damping device. However, verification of performance for this system should be carried out since this system is under developing status in our country. Especially, the durability for each part of this system should be guaranteed. Durable properties of driver plate which is the key component of dual mass flywheel were first investigated both in the raw (SCM435 in JIS) and heat-treated material. In addition, fatigue life analysis of driver plate was preformed in the real condition and the results were verified by comparison with the results of rig test.

• 한국세라믹학회지
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• 제31권11호
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• pp.1387-1395
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• 1994

Re-hydration properties of heated and ground CaO-SiO2-H2O system were studied under hydrothermal condition in order to examine the possibility of recycling ALC waste as raw materials of ALC. Powder of calcium silicate hydrates and ALC waste without heat treatment did not show further hydration while those of heat-treated at proper temperature showed re-hydration properties under hydrothermal condition. The lath-like shape of initially synthesized tobermorite was gradually turned into small debris during heating and plate-like tobermorite was crystallized during re-hydration of the heated powders. Heated and ground ALC waste could be added to natural raw mix for ALC at the ammount up to 20% with increased compressive strength and up to 30% with slightly decreased compressive strength. The optimum heating temperature of ALC for recycling was about 50$0^{\circ}C$.

• 대한의용생체공학회:의공학회지
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• 제19권4호
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• pp.333-339
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• 1998

본 연구에서는 혈관폐색을 위한 색전코일의 열처리 제조공정 조건을 연구하였다. 2.92mm의 알루미나 심재에 1차코일을 감은 후 475$^{\circ}C$와 600$^{\circ}C$에서 열처리하여 2차코일을 제조하였으며, 열처리 시간에 따른 2차코일의 피치간격, 내경 및 형상복원성을 평가하였다. 2차코일의 피치간격은 475$^{\circ}C$와 600$^{\circ}C$에서 각각 잠복기를 가진 후 열처리 시간이 증가함에 따라 증가하였다. 2차코일의 내경은 열처리 시간이 증가함에 딸 연속적으로 감소하였다. 이 원인은 열처리 초기에 회복에 의하여 재료의 내부에너지가 감소되면서 2차코일의 피치간격과 내경이 감소되나, 열처리 시간이 증가됨에 따라 텅스텐 표면의 산화물이 형성되면서 탄성이 증가되기 때문에 피치간격이 증가하는 것으로 분석되었다. 2차코일의 형상복원성은 텅스텐코일의 표면에 형성된 텅스텐 산화물이 탄성을 증가시킴으로 인해 열처리 시간이 증가함에 따라 연속적으로 증가하였다. 열처리 온도 영향을 비교하면 산화물형성 속도가 빠른 600$^{\circ}C$가 475$^{\circ}C$보다 더 우수한 형상복원성을 나타내었다. 텅스텐 색전코일의 제조공정 연구결과 2차코일의 피치간격, 내경 및 형상 복원성을 최적화하기 위해서는 600$^{\circ}C$에서 20분간 열처리하는 것이 적절한 조건인 것으로 조사되었다.