scholarly journals Effect of cooling process after rolling on microstructure and property of Nb-Ti micro-alloyed low-carbon bainite steel

2012 ◽  
Author(s):  
Defa Li ◽  
Haiyan Bao ◽  
Shisen Wang ◽  
Yuzhang Xiong ◽  
Shuqing Xing
Keyword(s):  
Low Carbon ◽  
Cooling Process ◽  
Bainite Steel ◽  
Low Carbon Bainite

The Corrosion Behavior of a Low Carbon Bainite Steel in Simulated Atmosphere Environment Containing Chloride and/or Sulfide

2012 ◽  
Vol 217-219 ◽  
pp. 419-427
Author(s):  
Lei Cui ◽  
Shan Wu Yang ◽  
Jun Hua Kong
Keyword(s):  
Steel Corrosion ◽  
Weathering Steel ◽  
Low Carbon ◽  
Three Solutions ◽  
Corrosion Rates ◽  
Bainite Steel ◽  
Selective Corrosion ◽  
Corrosion Behaviors ◽  
Low Carbon Bainite ◽  
Atmosphere Environment

The corrosion behaviors of a low carbon bainite steel in three atmosphere environments simulated by corresponding solutions were investigated in this accelerated test. It is found that the corrosion rate of the low carbon bainite steel is lower than that of the commercial weathering steel 09CuPCrNi in all the three solutions. The corrosion rates of the bainite steel in the three solutions are also different, which is most serious in the solution containing both chloride and sulfide. There is no serious selective corrosion, for the corrosion has little effect on the mechanical property of the bainite steel. Corrosion rates are relation to the amount of Cu and Cr enrichment in rust layers, which are well corresponding to the specific surface area values of corrosion products. Inhibit effect can be found in the solution containing both chloride and sulfide.

Effect of Heat Treatment on Microstructure and Mechanical Properties of 800MPa Grade Ultra Low Carbon Bainite Steel

2011 ◽  
Vol 415-417 ◽  
pp. 943-946 ◽  
Author(s):  
Zhan Lei Wei ◽  
Long Fei Zuo ◽  
Ben Ma ◽  
Li Xian Zhang ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Control Process ◽  
Residual Austenite ◽  
Polygonal Ferrite ◽  
Low Carbon ◽  
Ti Alloys ◽  
Bainite Steel ◽  
Low Carbon Bainite ◽  
Quenching And Tempering ◽  
Strength And Ductility

A new kind of bainite steel with ultra-low carbon content and Nb, Ti alloys has been developed. By applying thermomechanical control process, water quenching and tempering at different temperature, excellent properties have been obtained when tempered at 450°C, with the yield strength of 813MPa and elongation of 16.2%. The morphology observed by SEM shows that the microstructure consists of fine lath-shaped bainite, polygonal ferrite, quasi-polygonal ferrite and a small fraction of residual austenite or martensite-austenite constituents. In a TEM study plenty of precipitates with the size about 5-10nm were observed interacting with the dislocations, which is very significant for the optimization of strength and ductility.

Effects of Final Cooling Temperature on Microstructure Transformation and Properties of Q550 Low Carbon Bainite Steel

2020 ◽  
Vol 993 ◽  
pp. 550-558
Author(s):  
Zeng Qiang Man ◽  
Wei Yu ◽  
Huan Yang ◽  
Wen Gao Chang ◽  
Yun Fei Cao
Keyword(s):  
Great Influence ◽  
Granular Bainite ◽  
Low Carbon ◽  
Continuous Cooling Transformation ◽  
Cooling Temperature ◽  
Continuous Cooling ◽  
Bainite Steel ◽  
Lath Bainite ◽  
Transformation Curve ◽  
Low Carbon Bainite

The mechanical properties of low carbon bainite steel are closely related to the microstructure and proportion after phase transformation. The microstructure of the deformed austenite of low carbon bainite steel after isothermal transformation and continuous cooling transformation was studied by thermal simulation test. The metallographic structure was observed by optical microscopy (OM) and scanning electron microscopy (SEM). The metallographic and microhardness were used to judge the microstructure type, and the CCT (continuous cooling transformation) curve and TTT (time-temperature-transformation) curve of the test steel were drawn. It was found that at 700-430 °C isothermal, undergo a variety of medium-temperature microstructure transformations appeared for the test steels, such as ferrite, pearlite, granular bainite and lath bainite. The cooling rate and final cooling temperature have great influence on the type and performance of the final microstructure. The final cooling temperature was controlled at about 515°C. The mixed microstructures of granular bainite (GB) and fine martensite-austenite (M-A) island, a small amount of acicular ferrite and lath bainite were obtained. The yield and tensile strengths of this type of microstructure reached 639 MPa and 750 MPa respectively, the shrinkage rate reached 17%, and the better low-temperature impact performance was realized.

The Evolution of M/A in Ultra-Low Carbon Bainite Steel

2013 ◽  
Vol 652-654 ◽  
pp. 952-957
Author(s):  
Yi Nie ◽  
Cheng Jia Shang ◽  
Xin Lai He
Keyword(s):  
Cooling Rate ◽  
Transformation Process ◽  
Low Carbon ◽  
Hard Phase ◽  
Bainitic Steels ◽  
Bainite Steel ◽  
Tempering Treatment ◽  
Low Carbon Bainite ◽  
Size And Structure

The amount, size and structure of M/A in ultra low carbon bainitic steels，which are mainly affect by the transformation process, the cooling rate and the tempering treatments, have been investigated. The different cooling rate induce the variation of distribution of amount and size of M/A. There are bigger M/A mass with harder phase at low cooling rate while smaller M/A with less hard phase at high cooling rate. A series tempering tests have been carried out, which indicating that the tempering treatment has significant effect on the evolution of M/A.

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