Refined Bainite Microstructure and Mechanical Properties of a High-Strength Low-Carbon Bainitic Steel Treated by Austempering Below and Above MS

2018 ◽  
Vol 89 (4) ◽  
pp. 1700469 ◽  
Author(s):  
Junyu Tian ◽  
Guang Xu ◽  
Mingxing Zhou ◽  
Haijiang Hu
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Bainitic Steel ◽  
Low Carbon ◽  
Microstructure And Mechanical Properties ◽  
Bainite Microstructure

Isothermal Transformation, Microstructure and Mechanical Properties of Ausformed Low-Carbon Carbide-Free Bainitic Steel

2018 ◽  
Vol 941 ◽  
pp. 329-333 ◽  
Author(s):  
Jiang Ying Meng ◽  
Lei Jie Zhao ◽  
Fan Huang ◽  
Fu Cheng Zhang ◽  
Li He Qian
Keyword(s):  
Mechanical Properties ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Bainitic Ferrite ◽  
Isothermal Transformation ◽  
Bainitic Transformation ◽  
Isothermal Treatment ◽  
Bainitic Steel ◽  
Low Carbon ◽  
Microstructure And Mechanical Properties

In the present study, the effects of ausforming on the bainitic transformation, microstructure and mechanical properties of a low-carbon rich-silicon carbide-free bainitic steel have been investigated. Results show that prior ausforming shortens both the incubation period and finishing time of bainitic transformation during isothermal treatment at a temperature slightly above the Mspoint. The thicknesses of bainitic ferrite laths are reduced appreciably by ausforming; however, ausforming increases the amount of large blocks of retained austenite/martenisite and decreases the volume fraction of retained austenite. And accordingly, ausforming gives rise to significant increases in both yield and tensile strengths, but causes noticeable decreases in ductility and impact toughness.

Electron Microscope studies of the microstructures in as-quenched and aged HSLA-100 production steels and correlation with mechanical properties

1991 ◽  
Vol 49 ◽  
pp. 582-583
Author(s):  
A.G. Fox ◽  
V.R. Mattes ◽  
S. Mikalac ◽  
M.G. Vassilaros
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Low Carbon ◽  
Austenite Grain Size ◽  
Solid Solution Strengthening ◽  
Austenite Grain ◽  
Microstructure And Mechanical Properties ◽  
Hsla Steels ◽  
Carbonitride Precipitation ◽  
Strength And Toughness

Because of their excellent weldability, high strength low alloy (HSLA) ultra low carbon bainitic (ULCB) steels are finding increasing applications in ship and submarine construction. In order to achieve the required strength and toughness in ULCB HSLA steels it is necessary to control chemical composition and thermo-mechanical processing very carefully so that the desired microstructure and mechanical properties can be achieved. For instance HSLA 100 ULCB steel (nominal yield strength 100 ksi) used by the U.S. Navy in shipbuilding applications can derive its strength and toughness from the following sources:- (1) solid solution strengthening (2) small prior austenite grain size derived from niobium carbonitride precipitation at austenite grain boundaries (3) dislocation substructure and (4) from copper precipitates (in aged alloys). The object of the present work is to correlate the microstructure and mechanical properties of production batches of HSLA 100 in the quenched and aged conditions. Because many of the salient features of these microstructures are submicron in size it was found necessary to use SEM and TEM.

scholarly journals Effect of Electro Slag Remelting (ESR) on the microstructure and mechanical properties of low carbon bainitic steel

2018 ◽  
Vol 56 (04) ◽  
pp. 253-263
Author(s):  
E. Entezari ◽  
B. Avishan ◽  
H. Mousalou ◽  
S. Yazdani
Keyword(s):  
Mechanical Properties ◽  
Bainitic Steel ◽  
Low Carbon ◽  
Microstructure And Mechanical Properties

scholarly journals Microstructure and Mechanical Properties of Low-Carbon High-Strength Steel Fabricated by Wire and Arc Additive Manufacturing

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 216
Author(s):  
Laibo Sun ◽  
Fengchun Jiang ◽  
Ruisheng Huang ◽  
Ding Yuan ◽  
Chunhuan Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
High Strength Steel ◽  
High Strength ◽  
Taylor Factor ◽  
Image Correlation ◽  
Experimental Fact ◽  
Fracture Mechanisms ◽  
Low Carbon ◽  
Microstructure And Mechanical Properties

Wire and arc additive manufacturing (WAAM) is a novel technique for fabricating large and complex components applied in the manufacturing industry. In this study, a low-carbon high-strength steel component deposited by WAAM for use in ship building was obtained. Its microstructure and mechanical properties as well as fracture mechanisms were investigated. The results showed that the microstructure consisted of an equiaxed zone, columnar zone, and inter-layer zone, while the phases formed in different parts of the deposited component were different due to various thermal cycles and cooling rates. The microhardness of the bottom and top varied from 290 HV to 260 HV, caused by temperature gradients and an inhomogeneous microstructure. Additionally, the tensile properties in transversal and longitudinal orientations show anisotropy characteristics, which was further investigated using a digital image correlation (DIC) method. This experimental fact indicated that the longitudinal tensile property has an inferior performance and tends to cause stress concentrations in the inter-layer areas due to the inclusion of more inter-layer zones. Furthermore, electron backscattered diffraction (EBSD) was applied to analyze the difference in Taylor factor between the inter-layer area and deposited area. The standard deviation of the Taylor factor in the inter-layer area was determined to be 0.907, which was larger than that in the deposited area (0.865), indicating nonuniform deformation and local stress concentration occurred in inter-layer area. Finally, as observed from the fracture morphology on the fractured surface of the sample, anisotropy was also approved by the comparison of the transversal and longitudinal tensile specimens.

Effect of Aging Temperature on the Microstructure and Mechanical Properties of 1000MPa Grade Low Carbon Bainitic Steel

2012 ◽  
Vol 152-154 ◽  
pp. 376-380 ◽  
Author(s):  
Long Fei Zuo ◽  
Zhan Lei Wei ◽  
Ri Ni ◽  
Ben Ma ◽  
Zi Dong Wang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Yield Strength ◽  
Aging Temperature ◽  
Granular Bainite ◽  
Bainitic Steel ◽  
Low Carbon ◽  
Microstructure And Mechanical Properties ◽  
Effect On Yield ◽  
Hot Rolled

A kind of 1000MPa low carbon bainitic steel belonged to the Fe-Cu-Nb series was hot rolled and aged, the influence of aging temperatures on the microstructure and mechanical properties of the steel were investigated by using Scanning electron microscopy (SEM) and transmission electron microscopy(TEM). The results show that the microstructure of the low carbon bainitic steel consisted of lath-shaped bainite(LB), granular bainite(GB) and quasi-polygonal ferrite(QF), and the proportion of each kind of microstructure changed with the aging temperatures. The strength of steel with the increase of aging temperature first increased, then decreased, Aging temperatures had distinct effect on yield strength of the tested steel, and less effect on the ultimate tensile strength, we can get the best comprehensive properties yield strength 1011.87 MPa and elongation rate 16.38% of good tough match aged at 450°C. Through analysis it is concluded that the strength of the tested steels aged at 450°C reaches the maximum value, which is attributed to the precipitation of a large amount of fine ε-Cu particles(5~10nm) and a small number of(Nb,Ti)(C,N) precipitates.

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