Ultra-fine grain size and isotropic very high strength by direct extrusion of chill-cast Mg–Zn–Y alloys containing quasicrystal phase

2011 ◽  
Vol 64 (7) ◽  
pp. 661-664 ◽  
Author(s):  
Alok Singh ◽  
Yoshiaki Osawa ◽  
H. Somekawa ◽  
T. Mukai
Keyword(s):  
Grain Size ◽  
High Strength ◽  
Direct Extrusion ◽  
Fine Grain ◽  
Chill Cast ◽  
Very High

The Study on the Fabrication of Nano-Structured Steel by Cold Rolling and Annealing of Martensite

2013 ◽  
Vol 634-638 ◽  
pp. 1807-1810
Author(s):  
Guang Xu ◽  
Jing Yang ◽  
Tao Xiong ◽  
Peng Deng ◽  
Long Fei Cao
Keyword(s):  
Grain Size ◽  
Cold Rolling ◽  
High Strength ◽  
Total Elongation ◽  
Plain Carbon Steel ◽  
Mean Grain Size ◽  
Cold Rolling And Annealing ◽  
The Mean ◽  
Martensite Microstructure ◽  
Very High

Sub-nano structured steel was obtained by cold rolling and annealing martensite microstructure for a plain carbon steel. The mean grain size is several hundreds nanometer. The steel has very high strength and also good total elongation.

Improvement of Strength and Ductility by Combining Static Recrystallization and Unique Heat Treatment in Co-20Cr-15W-10Ni Alloy for Stent Application

2021 ◽  
Vol 1016 ◽  
pp. 1503-1509
Author(s):  
Kosuke Ueki ◽  
Soh Yanagihara ◽  
Kyosuke Ueda ◽  
Masaaki Nakai ◽  
Takayoshi Nakano ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Static Recrystallization ◽  
High Strength ◽  
Small Variation ◽  
Grain Structure ◽  
Fine Grain ◽  
High Temperature Short Time ◽  
Average Grain Size ◽  
Strength And Ductility

The Co-20Cr-15W-10Ni (CCWN, mass%) alloy has excellent corrosion resistance and strength-ductility balance and is applied in almost all balloon-expandable stent platforms. To further reduce the invasiveness of stent placement, it is necessary to reduce the diameter of the stent. That is, both high strength and high ductility should be achieved while maintaining a low yield stress. In our previous studies, it was discovered that low-temperature heat-treatment (LTHT) at 873 K improves the elongation of the CCWN alloy. In this study, we focused on the grain refinement by swaging and static recrystallization to improve the strength of the alloy. The as-swaged alloy was recrystallized at 1373–1473 K for 100–300 s, followed by LTHT. A fine grain structure with an average grain size of 3–17 μm was obtained by static recrystallization. The η-phase (M12X-M6X type precipitates, M: metallic elements, X: C and/or N) formed during the recrystallization at 1373–1448 K. The alloys recrystallized at 1448 and 1473 K had a homogeneous structure with a small variation in the grain size. On the other hand, the alloys recrystallized at 1373 and 1423 K had an inhomogeneous structure in which fine and coarse grains were mixed. Both the strength and ductility of the CCWN alloy were improved by combining high-temperature short-time recrystallization and LTHT.

Fabrication of very-high-strength pure copper with fine grain structure through multi-axial diagonal forging

2020 ◽  
Vol 269 ◽  
pp. 127663
Author(s):  
Jae Kun Lee ◽  
Sang-Chul Kwon ◽  
Hyo-Tae Jeong ◽  
Sang-Ho Han ◽  
Sung Hyuk Park
Keyword(s):  
Pure Copper ◽  
High Strength ◽  
Grain Structure ◽  
Fine Grain ◽  
Very High

Research and Development of U68CuCr Rail Steel

2012 ◽  
Vol 482-484 ◽  
pp. 989-995
Author(s):  
Yu Ji ◽  
Zhong Min Yang ◽  
Min Zhu ◽  
Wan Ling Zhang
Keyword(s):  
Grain Size ◽  
Chemical Composition ◽  
Research And Development ◽  
Production Process ◽  
Rail Steel ◽  
High Strength ◽  
Immersion Test ◽  
Corrosion Resistant ◽  
Fine Grain ◽  
Hot Rolled

According to characteristics of the marine environment corrosion, 980MPa steel were developed. After design rational chemical composition and production process, the full section hot-rolled corrosion-resistant sorbite rail steel were successfully developed. this kind of steel has fine grain size, high strength and perfect toughness. Dry-wet immersion test showed that lift of this rail is 70% longer than U75V.

Ultra-fine grain size and exceptionally high strength in dilute Mg–Ca alloys achieved by conventional one-step extrusion

2019 ◽  
Vol 237 ◽  
pp. 65-68 ◽  
Author(s):  
Hucheng Pan ◽  
Changlin Yang ◽  
Yantao Yang ◽  
Yongqiang Dai ◽  
Dengshan Zhou ◽  
...  
Keyword(s):  
Grain Size ◽  
High Strength ◽  
Fine Grain ◽  
One Step

Optimization of the Post Heat Treatment of Additively Manufactured IN718

2021 ◽  
Author(s):  
Alber Sadek
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
High Performance ◽  
High Strength ◽  
Fatigue Properties ◽  
Primary Carbide ◽  
Soaking Time ◽  
Fine Grain ◽  
Annealing Cycle ◽  
Treatment Procedures

Abstract IN718 has good fabricability, high strength at elevated temperature, and corrosion resistance, and it is widely deployed in many aerospace and other high-performance applications. With the molten pool rapid solidification during laser powder bed fusion (L-PBF), the resulting microstructure is anisotropic and inhibits macro-segregation. The as-built condition usually exhibits lower mechanical properties. Four different heat treatment procedures were designed and tested to study the effect of different heat treatment parameters on the type of precipitates and grain size. The investigated heat treatment procedures showed the formation of equiaxed grain size and a significant amount of γ' and γ" particles at the grain boundary in addition to primary carbide types (MC). Three types of microstructure characteristics and grain size were achieved. Coarse grain size suitable for creep application was achieved by increasing the soaking time at the aging cycle. The formation of serrated grain boundaries suitable for good fatigue and creep properties was achieved by decreasing the stress relief cycle's soaking time and temperature. Fine-grain size, which is preferable for fatigue properties, was achieved by decreasing the soaking time at the solution annealing cycle.

Grain Size Effect on Low Cycle Fatigue Behavior of High Strength Structural Materials

2016 ◽  
Vol 258 ◽  
pp. 269-272
Author(s):  
Ryuichiro Ebara
Keyword(s):  
Grain Size ◽  
Fatigue Strength ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
High Strength ◽  
Grain Size Effect ◽  
Cycle Fatigue ◽  
Fracture Surfaces ◽  
Fine Grain ◽  
Number Of Cycles

This paper presents grain size effect on low cycle fatigue behavior of high strength maraging steel with gain size of 20,60 and 100μm and Ti-6Al-4V alloy with grain size of 0.5,1.4 and 5.1μm. Low cycle fatigue strength of the maraging steel depends on grain size in number of cycles up to 103.The smaller the grain size, the higher the low cycle fatigue strength was. Quasci-cleavage fracture surfaces were predominant for material with grain size of 20μm,while intergranular fracture surfaces were predominant for materials with larger grain size in number of cycles lower than 60. Striation was predominant for all tested materials in number of cycles higher than 60.Low cycle fatigue strength of Ti-6Al-4V alloy also depends on grain size in number of cycles up to 104. Grain size dependent transgranular fracture surfaces were predominant for materials with ultra-fine grain size of 0.5μm and fine grain size of 1.4μm.

Fatigue of Ultra-Fine Grained α-Brass

2014 ◽  
Vol 891-892 ◽  
pp. 1125-1130
Author(s):  
Yoshikazu Nakai ◽  
Takuto Imanaka ◽  
Daiki Shiozawa
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Severe Plastic Deformation ◽  
Fatigue Limit ◽  
High Strength ◽  
Angular Pressing ◽  
Fine Grain ◽  
Proof Strength

Combined methods to obtain ultra-fine grain (UFG) α-brass samples are proposed. Severe plastic deformation followed by recrystallization was conducted, where multiple rolling and equal channel angular pressing (ECAP) were employed. Recrystallization was accomplished by heat-treatment after the severe plastic deformation, and the grain size after the severe plastic deformation was decreased. By multiple rolling, plates with thickness of 0.1 mm and grain size of 1.0 μm were obtained. By ECAP process, square bar with cross-section of 6 mm × 6 mm and minimum grain size of 4.1 μm was obtained. The 0.2 % proof strength, ultimate tensile strength, and fatigue limit were increased with the value of inverse square root of grain size (Hall-Petch relationship). Then, the 0.2 % proof strength of UFG brass was tenfold, the ultimate tensile strength and the fatigue limit were two fold increases from the conventional α-brass. Because of the high strength, the scatter of fatigue strength of UFG brass was large, which reflects the sensitivity to defects in material.

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