scholarly journals Effect of [NO2-]/[Cl-] Ratio on Corrosion Behavior of Fine- grain High-strength Reinforcement in Simulated Concrete Pore Solutions

2016 ◽  
pp. 3824-3842
Author(s):  
Bilan Lin ◽  
Keyword(s):  
Corrosion Behavior ◽  
High Strength ◽  
Fine Grain

Design of a novel HSLA steel with a combination of high strength (140–160 ksi) and excellent toughness

2021 ◽  
Vol 112 (10) ◽  
pp. 800-811
Author(s):  
Mehdi Soltan Ali Nezhad ◽  
Sadegh Ghazvinian ◽  
Mahmoud Amirsalehi ◽  
Amir Momeni
Keyword(s):  
Impact Toughness ◽  
Yield Strength ◽  
Hsla Steel ◽  
Charpy Impact ◽  
High Strength ◽  
Controlled Rolling ◽  
The Other ◽  
Grain Structure ◽  
Charpy Impact Toughness ◽  
Fine Grain

Abstract Three steels were designed based on HSLA-100 with additional levels of Mn, Ni, Cr and Cu. The steels were prepared by controlled rolling and tempered at temperatures in range of 550–700°C. The continuous cooling time curves were shifted to longer times and lower temperatures with the increased tendency for the formation of martensite at lower cooling rates. The microstructures revealed that controlled rolling results in austenite with uniform fine grain structure. The steel with the highest amount of Mn showed the greatest strength after tempering at 750 °C. The top strength was attributed to the formation of Cu-rich particles. The steel with 1.03 wt.% Mn, tempered at 650 °C exhibited the best Charpy impact toughness at –85°C. On the other hand, the steel that contained 2.11 wt.% Mn and tempered at 700 °C showed the highest yield strength of 1 097.5 MPa (∼159 ksi) and an impact toughness of 41.6 J at –85°C.

scholarly journals Evaluation of Microstructure and Selected Mechanical Properties of Laser Beam Welded S690QL High-Strength Steel

2018 ◽  
Vol 18 (3) ◽  
pp. 34-42 ◽  
Author(s):  
L. Tuz
Keyword(s):  
Mechanical Properties ◽  
Laser Beam ◽  
High Strength Steel ◽  
High Strength ◽  
Fine Grain ◽  
Steel Material ◽  
Bainitic Structure ◽  
Haz Width ◽  
Quenching And Tempering ◽  
Softened Zone

AbstractThe paper presents results of microstructure and mechanical properties investigation of laser beam welded high-strength steel. Material for test was non-alloyed steel with yield strength of 690 MPa after quenching and tempering in delivery condition. Research carried out on the butt-welded joints shows fine-grain martensitic-bainitic structure of base metal and in the weld. Investigations of mechanical properties revealed the softened zone in HAZ where the hardness decrease without microstructural changes was observed. Moreover, an influence of softened zone and HAZ width on impact strength was observed where the occurrence of lower hardness led to fracture path deviation phenomenon.

Experimental Investigation on HRBF500 RC Circular Pile under Low Cyclic Reversed Loading

2011 ◽  
Vol 105-107 ◽  
pp. 1250-1254
Author(s):  
Qian Fu ◽  
Shu Ting Liang ◽  
Xiao Jun Zhu
Keyword(s):  
Seismic Design ◽  
Seismic Behavior ◽  
High Strength ◽  
Skeleton Curve ◽  
Failure Patterns ◽  
Concrete Piles ◽  
Fine Grain ◽  
Steel Bars ◽  
Reversed Loading ◽  
Ductile Behavior

Six concrete piles reinforced with 500MPa fine-grain steel bars were tested under low cycle reversed loading to study the seismic behavior such as failure patterns, characteristics of hysteretic and skeleton curve. Three parameters, longitudinal reinforcement strength, reinforcement ratio and axial compression ratio were taken into consideration. The main failure patterns as well as hysteretic curve of those piles were obtained, and influence of each of the three parameters on the ductile behavior, ability of energy dissipation and law of strength degeneration were analyzed. The experimental results indicate that the mechanical behavior of reinforced concrete low cyclic reversed loading columns with fine grain high strength reinforcement is similar to normal reinforced columns. The concrete piles reinforced with 500MPa fine-grain steel bars show good seismic performance and 500MPa fine-grain steel bars can be used in seismic design.

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.

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