The Influences of Soaking Temperature and Over-Aging Temperature on the Microstructures and Mechanical Properties of Low Carbon DP980

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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Effect of Rare Earth Cerium Addition on Microstructures and Mechanical Properties of Low Carbon High Manganese Steels

High Temperature Materials and Processes ◽

10.1515/htmp-2015-0183 ◽

2017 ◽

Vol 36 (2) ◽

pp. 145-153 ◽

Cited By ~ 4

Author(s):

M. Z. Jiang ◽

Y. C. Yu ◽

H. Li ◽

X. Ren ◽

S. B. Wang

Keyword(s):

Mechanical Properties ◽

Induction Furnace ◽

Lattice Misfit ◽

Vacuum Induction Furnace ◽

Low Carbon ◽

High Manganese ◽

Calculation Results ◽

High Manganese Steels ◽

Microstructures And Mechanical Properties ◽

Manganese Steels

AbstractLow carbon high manganese steels with different Ce contents were melted in medium frequency vacuum induction furnace. The microstructures and mechanical properties of steels were studied by OM, SEM, EDS and mechanical property testing. The results showed that the microstructures of experimental steels were refined remarkably, inclusions distributed more finely and uniformly, the tensile strength and impact toughness of tested steels both improved greatly after the addition of Ce. Thermodynamic calculation results demonstrated that Ce contained inclusions were Ce2O3 and Ce3S4, which agreed well with the results observed by SEM and EDS. By analysis of two-dimensional lattice disregistry, it was shown that the lattice misfit parameter between δ-Fe and Ce2O3, Ce3S4 are less than 6 %, which indicated that Ce2O3 and Ce3S4 could effectively act as the heterogeneous nuclei of initial δ-Fe. Therefore, the microstructures were refined significantly and the mechanical properties were improved correspondingly in Ce-added low carbon high manganese steels.

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Microstructures and Mechanical Properties of an Al-Cu-Li-Mg-Zr Alloy Containing Zn and Mn

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.995 ◽

2007 ◽

Vol 546-549 ◽

pp. 995-1002 ◽

Cited By ~ 1

Author(s):

Yong Lai Chen ◽

Jin Feng Li ◽

Yu Wei Zhang ◽

Zi Qiao Zheng

Keyword(s):

Mechanical Properties ◽

Aging Temperature ◽

Solution Treatment ◽

Heat Treatments ◽

Alloying Elements ◽

Solution Temperature ◽

Lower Strength ◽

Microstructures And Mechanical Properties ◽

Zr Alloy

An Al-3.43Cu-1.28Li-0.49Mg-0.12Zr containing 0.62Zn and 0.29Mn was designed and the microstructures and mechanical properties of the alloy with various heat treatments were investigated. The precipitates of the alloy consist of T1 (Al2CuLi), θ′ (Al2Cu) σ (Al5Cu6Mg2) and δ′ (Al3Li). As solution temperature is changed from 485°C to 530°C, the solution degree of alloying elements in alloy increased, the amount of T1 in the alloy aged at 160°C for 18 h increased and that of θ′ is decreased, resulting in an increase of strength. After solution treatment at 530°C, the alloy aged for 18 h at 145°C is mainly strengthened by G P zones, and a little amount of T1 precipitates. As aging temperature is increased to 160°C and 175°C, the strength increased, due to the sufficient precipitation of σ and T1. The smaller amount of T1 in the alloy aged at 190°C is consistent with its lower strength. Meanwhile, it is found that the σ precipitate does not coarsen as aging temperature increases in the range from 160°C to 190°C.

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