Microstructural Evaluation of Isothermally Aged 12Cr Steel by Magnetic Property Measurement

2006 ◽  
Vol 324-325 ◽  
pp. 1253-1256
Author(s):  
C.S. Kim ◽  
J.H. Kang ◽  
Jai Won Byeon ◽  
S.I. Kwun
Keyword(s):  
Mechanical Properties ◽  
Magnetic Property ◽  
Aging Time ◽  
Thermal Aging ◽  
Isothermal Aging ◽  
Martensite Lath ◽  
M23c6 Carbide ◽  
Linear Relations ◽  
Microstructural Evaluation ◽  
Property Measurement

The magnetic coercivity of ferritic 12Cr steel was experimentally studied in order to characterize its microstructures and mechanical properties during isothermal aging. As the aging time increased, the M23C6 carbide coarsened and additional precipitation of Fe2W phase was induced. The width of martensite lath increased to about 0.4μm after 4000 hrs of aging. The coercivity decreased as the number of precipitate decreased and the width of martensite lath increased. The hardness was proportional to the magnetic coercivity. These empirical linear relations suggested that the change in the microstructures and strength of ferritic 12Cr steel during thermal aging could be evaluated by monitoring the magnetic coercivity.

scholarly journals Effect of Thermal Aging on the Mechanical Properties of High Tenacity Polyester Yarn

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1666
Author(s):  
Tsegaye Sh. Lemmi ◽  
Marcin Barburski ◽  
Adam Kabziński ◽  
Krzysztof Frukacz
Keyword(s):  
Mechanical Properties ◽  
Structural Change ◽  
Aging Time ◽  
Thermal Aging ◽  
Temperature Influence ◽  
Polyester Yarn ◽  
Textile Materials ◽  
Conveyor Belts ◽  
Effects Of Aging ◽  
Vulcanization Process

Textile materials produced from a high tenacity industrial polyester fiber are most widely used in the mechanical rubber goods industry to reinforce conveyor belts, tire cords, and hoses. Reinforcement of textile rubber undergoes a vulcanization process to adhere the textile materials with the rubber and to enhance the physio-mechanical properties of the product. The vulcanization process has an influence on the textile material being used as a reinforcement. In this work, the effects of aging temperature and time on the high tenacity polyester yarn’s mechanical and surface structural properties were investigated. An experiment was carried out on a pre-activated high tenacity polyester yarn of different linear densities, by aging the yarn specimens under various aging temperatures of 140, 160, 200, and 220 °C for six, twelve, and thirty-five minutes of aging time. The tensile properties and surface structural change in the yarns pre- and post-aging were studied. The investigation illustrates that aging time and temperature influence the surface structure of the fiber, tenacity, and elongation properties of the yarn. Compared to unaged yarn, an almost five times higher percentage of elongation was obtained for the samples aged at 220 °C for 6 min, while the lowest tenacity was obtained for the sample subjected to aging under 220 °C for 35 min.

scholarly journals Effects of In Content on the Microstructure and Mechanical Properties of In–Bi Alloys During Isothermal Aging

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 548
Author(s):  
Sanghun Jin ◽  
Omid Mokhtari ◽  
Shutetsu Kanayama ◽  
Hiroshi Nishikawa
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Aging ◽  
Isothermal Aging ◽  
Tensile Tests ◽  
Melting Temperatures ◽  
Microstructure And Mechanical Properties ◽  
Ductile Fractures ◽  
Fracture Surface Analysis ◽  
Bulk Alloys

Bulk In–Bi binary alloys with 50, 40, 33.7, and 30 mass% Bi and low melting temperatures were prepared and aged at 40 °C for 168, 504, and 1008 h in an oil bath. Tensile tests were performed on the bulk alloys, followed by fracture surface analysis of the tensile test samples. The effect of In content on the microstructures and mechanical properties of the alloys during thermal aging was analyzed. Ultimately, the tensile strength of the In–Bi alloys was found to decrease with aging time, while the elongation of the In–Bi alloys increased after thermal aging. The results of the tensile tests indicate that a higher In content improved the ductility of the In–Bi alloys significantly and reduced their strength. In addition, the fracture surfaces exhibited ductile fractures in the neck shapes. A comparative analysis of the microstructure and mechanical properties of the aforementioned alloys during thermal aging was also conducted.

Microstructures Evolution of a Ni-Base Superalloy after Long-Term Aging at 750°C

2007 ◽  
Vol 561-565 ◽  
pp. 387-390
Author(s):  
Tong Cui ◽  
Ji Jie Wang ◽  
Li Qing Chen ◽  
Guang Pu Zhao ◽  
Hong Cai Yang
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Aging Time ◽  
Aging Process ◽  
M23c6 Carbide ◽  
New Type ◽  
Base Superalloy

The microstructures evolution of a new type Ni-base superalloy has been investigated after long-term aging at 750°C for 2000h. The results indicate that TCP, a harmful phase greatly affects the mechanical properties of the alloy, is un-precipitated in the aging process. γ´ phase is precipitated in two kinds of sizes during long-term aging. The shape of larger one is transit from spherical to cubic with prolonging of aging time. The M23C6 carbide formed mainly by Cr, and other elements such as Al, Ti, Co and Mo is also precipitated in both γ matrix and grain boundaries, and the quantities of the carbide increase gradually with the increasing of aging time.

scholarly journals Effect of Sizing Agents on Surface Properties of T800 Grade CF and Thermal Aging Time on Mechanical Properties of T800 Grade CF/Epoxy Composites

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Tian Yang ◽  
Yan Zhao ◽  
Hansong Liu ◽  
Shu Xiong
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Aging Time ◽  
Surface Properties ◽  
Thermal Aging ◽  
Ageing Time ◽  
Flexural Modulus ◽  
Thermal Ageing ◽  
Epoxy Composites ◽  
Interlaminar Shear

This paper investigates the effect of sizing agent molecular weight on carbon fiber (CF) surface properties and the effect of thermal aging time on mechanical properties of CF/epoxy composites. The surface properties of three CCF800 CF samples with varying sizing agent molecular weight were characterized by surface morphology, surface roughness, chemical functional groups, and element composition. The results showed that the sample with low molecular weight exhibited low roughness and high proportion of activated carbon atoms. The flexural strength, flexural modulus, and interlaminar shear strength of CCF800/5228 composites were measured at 25°C and 150°C by thermal ageing time 0, 100 h, 250 h, 500 h, and 1000 h. The results showed that the thermal aging time up to 1000 h had little effect on the flexural modulus, and the interlaminar shear performance at 150°C showed a trend of increasing at the beginning and then decreasing.

Effect of Isothermal Aging on Magnetic Properties in 12Cr Steel

2006 ◽  
Vol 326-328 ◽  
pp. 1201-1204 ◽  
Author(s):  
C.S. Kim ◽  
Il Ho Kim ◽  
Ik Keun Park ◽  
C.Y. Hyun
Keyword(s):  
Magnetic Properties ◽  
Aging Time ◽  
Isothermal Aging ◽  
Martensite Lath ◽  
Aging Period ◽  
Lath Width

The magnetic coercivity of martensitic 12Cr steel was measured in order to evaluate its degree of isothermal aging. As the aging time increased, the lath width increased and the dislocations were recovered. Aging resulted in the coarsening of the as-tempered carbides (M23C6 and MX) followed by additional precipitation of Fe2W. The magnetic coercivity rapidly decreased during the initial aging period of about 1,000 hours and then decreased slightly thereafter. The decrease in the coercivity with increasing aging time was related to the decrease in the number of pinning sites, those associated with the dislocations, fine precipitates and coarsening of the martensite lath/subgrain.

Mechanical Properties of Epoxy Adhesive Under Thermal Aging and Their Chemical Degradation Behavior

2021 ◽  
Vol 21 (8) ◽  
pp. 4444-4449
Author(s):  
Bongjin Chung ◽  
Shin Sungchul ◽  
Jaeho Shim ◽  
Seongwoo Ryu
Keyword(s):  
Mechanical Properties ◽  
Thermal Aging ◽  
Photoelectron Spectroscopy ◽  
Thermal Exposure ◽  
Chain Scission ◽  
Epoxy Adhesive ◽  
Chemical Degradation ◽  
Adhesive Properties ◽  
Noticeable Reduction

Epoxy adhesive was analyzed under long term thermal aging and mechanical properties and chemical degradation were observed by X-ray photoelectron spectroscopy (XPS). Long term thermal exposure of epoxy causes a noticeable reduction in adhesive properties. We developed a predictive model of temperature and time dependent aging. The temperature dependent aging behavior of epoxy adhesive shows good agreement with conventional Arrhenius equations. Using XPS analysis, we also discovered a correlation between chemical degradation and the adhesive properties. Decay of C–C bonding ratio induced chain-scission of epoxy adhesive; increase of total numbers of C–O and C═O induced oxidation of epoxy adhesive during thermal exposure.

scholarly journals The Effect of Heat Treatment on the Microstructure and Mechanical Properties of the Novel Low-Cost Ti-3Al-5Mo-4Cr-2Zr-1Fe Alloy

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3798
Author(s):  
Meng Sun ◽  
Dong Li ◽  
Yanhua Guo ◽  
Ying Wang ◽  
Yuecheng Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aging Time ◽  
Volume Fraction ◽  
Low Cost ◽  
Solution Treatment ◽  
Solution Temperature ◽  
The Novel ◽  
Α Phase ◽  
The Cost

In order to reduce the cost of titanium alloys, a novel low-cost Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) titanium alloy was developed. The influence of heat treatment on the microstructure characteristics and mechanical properties of the new alloy was investigated. The results showed that the microstructure of Ti-35421 alloy consists of a lamina primary α phase and a β phase after the solution treatment at the α + β region. After aging treatment, the secondary α phase precipitates in the β matrix. The precipitation of the secondary α phase is closely related to heat treatment parameters—the volume fraction and size of the secondary α phase increase when increasing the solution temperature or aging time. At the same solution temperature and aging time, the secondary α phase became coarser, and the fraction decreased with increasing aging temperature. When Ti-35421 alloy was solution-treated at the α + β region for 1 h with aging surpassing 8 h, the tensile strength, yield strength, elongation and reduction of the area were achieved in a range of 1172.7–1459.0 MPa, 1135.1–1355.5 MPa, 5.2–11.8%, and 7.5–32.5%, respectively. The novel low-cost Ti-35421 alloy maintains mechanical properties and reduces the cost of materials compared with Ti-3Al-5Mo-5V-4Cr-2Zr (Ti-B19) alloy.

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