Study of Microstructure and Mechanical Properties of Hot-Rolled Ultra-High Strength Ferrite-Bainite Dual Phase Steel

2018 ◽  
Vol 921 ◽  
pp. 208-213 ◽  
Author(s):  
Zhuang Li ◽  
Wei Lv
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Dual Phase Steel ◽  
High Strength ◽  
Dual Phase ◽  
Finish Rolling ◽  
Fast Cooling ◽  
Hot Rolled ◽  
Low Temperature Rolling

Effects of thermo-mechanical control processing (TMCP) on microstructure and mechanical properties of hot-rolled ultra-high strength ferrite-bainite dual phase steel were investigated on a laboratory hot rolling mill. The results have shown that the microstructure containing ferrite and bainite can be obtained by TMCP. Ultimate tensile strength of all the specimens exceeded 1000MPa. Finish rolling temperatures affect the mechanical properties of ultra-high strength ferrite-bainite dual phase steel. Ultimate tensile strength reached 1078MPa at relatively low finish rolling temperature because of the ferrite grains refined. Fast cooling after low temperature rolling results in the ferrite grains refined and the formation of martensite islands. As a result, the product of ultimate tensile strength and total elongation (Rm×A50) of specimen 4 with fast cooling after low temperature rolling reaches the maximum value (18096MPa%).

The Effect of Large Reduction on the Microstructure and Properties for As-Hot Rolled Dual-Phase Nb-Bearing Steel

2011 ◽  
Vol 284-286 ◽  
pp. 1101-1105
Author(s):  
Hong Mei Zhang ◽  
Li Feng Qiao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Dual Phase Steel ◽  
Bearing Steel ◽  
Dual Phase ◽  
Large Reduction ◽  
Microstructure Refinement ◽  
The Matrix ◽  
Hot Rolled

The effect of reduction on the microstructure refinement and mechanical properties of the as-hot rolled dual-phase Nb-bearing steel were studied at laboratory. It is found that the dual-phase steel displays clearly classic dual phase morphology which is ferrite and martensite or bainsite, and the fine island or lath martinsite is dispersed on the matrix of ferrite by the observation of microstructure. The grain can be refined, and the increased precipitated second particles are fined and dispersed with the increasing of reduction. The mechanical properties determination result shows that the mechanical properties have greatly improved by large reduction. The tensile strength obtained in the laboratory is up to 680MPa, the ratio of yield strength and tensile strength is low, and the elongation is better.

Effects of Finish-Rolling Reduction on Microstructure and Mechanical Properties for C-Si-Mn Hot Rolled Dual-Phase Steel

2011 ◽  
Vol 339 ◽  
pp. 215-218
Author(s):  
Bin Bin Sun ◽  
Zhi Wei Jia ◽  
Hong Mei Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Dual Phase Steel ◽  
Lath Martensite ◽  
Rolling Reduction ◽  
Dual Phase ◽  
Fine Grain ◽  
Microstructure And Mechanical Properties ◽  
Finish Rolling ◽  
Hot Rolled

The experiments were carried out on the φ450 hot rolling mill at the State Key laboratory of Rolling and Automatic of Northeastern University. The effect of different finish-rolling reduction on the microstructure and mechanical properties of C-Si-Mn hot rolled dual-phase steel were studied. It is found that the grain size of the ferrite would be finer with the increasing of finish-rolling reduction. Through the controlling of the finish-rolling reduction, grain size of the ferrite can be finer, so the better properties can be obtained by fine grain and sub-grain strengthened. With the low volume of lath martensite, the elongation of sample is high, the yield-strength ratio is low, and complex properties are better.

scholarly journals Achievement of High Strength and Ductility in Al–Si–Cu–Mg Alloys by Intermediate Phase Optimization in As-Cast and Heat Treatment Conditions

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 647 ◽  
Author(s):  
Bingrong Zhang ◽  
Lingkun Zhang ◽  
Zhiming Wang ◽  
Anjiang Gao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Intermediate Phase ◽  
High Strength ◽  
Mg Alloys ◽  
Artificial Ageing ◽  
Treatment Conditions ◽  
Eutectic Si

In order to obtain high-strength and high-ductility Al–Si–Cu–Mg alloys, the present research is focused on optimizing the composition of soluble phases, the structure and morphology of insoluble phases, and artificial ageing processes. The results show that the best matches, 0.4 wt% Mg and 1.2 wt% Cu in the Al–9Si alloy, avoided the toxic effect of the blocky Al2Cu on the mechanical properties of the alloy. The addition of 0.6 wt% Zn modified the morphology of eutectic Si from coarse particles to fine fibrous particles and the texture of Fe-rich phases from acicular β-Fe to blocky π-Fe in the Al–9Si–1.2Cu–0.4Mg-based alloy. With the optimization of the heat treatment parameters, the spherical eutectic Si and the fully fused β-Fe dramatically improved the ultimate tensile strength and elongation to fracture. Compared with the Al–9Si–1.2Cu–0.4Mg-based alloy, the 0.6 wt% Zn modified alloy not only increased the ultimate tensile strength and elongation to fracture of peak ageing but also reduced the time of peak ageing. The following improved combination of higher tensile strength and higher elongation was achieved for 0.6 wt% Zn modified alloy by double-stage ageing: 100 °C × 3 h + 180 °C × 7 h, with mechanical properties of ultimate tensile strength (UTS) of ~371 MPa, yield strength (YS) of ~291 MPa, and elongation to fracture (E%) of ~5.6%.

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