Strain-Induced Precipitation in Nb-Bearing Low Carbon Multi-Microalloyed Steel

2010 ◽  
Vol 97-101 ◽  
pp. 560-564 ◽  
Author(s):  
Shao Qiang Yuan ◽  
Guo Li Liang ◽  
Xiao Juan Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Relaxation Process ◽  
Microalloyed Steel ◽  
Low Carbon ◽  
Precipitation Behavior ◽  
Simulation Test ◽  
Transmission Electron

Thermo-simulation test, transmission electron microscopy(TEM) and nanobeam EDS technique were used to investigate the strain induced precipitation behavior during relaxation process after deformed austenite in Mn-Mo-Nb-B low carbon multi-microalloyed Steel. The experiment results indicate that during isothermal held at 850 °Cand 900 °C after predeformation, the size of precipitates occurred in the Mn-Mo-Nb-B steel at different stage is smaller than that happened in the only Nb and Ti-bearing microalloyed steel. The ratio of Nb/Ti to precipitates increased with the relaxing time. After being held longer, Mo atoms would enter the lattice of (Nb,Ti)(C,N) precipitates and the amount in the precipitates increased with the relaxation as time prolonged.

Effect of Final Rapid Cooling Temperature on Ultra-Fine Carbides of Ti-Mo Ferrite Matrix Microalloyed Steel

2018 ◽  
Vol 926 ◽  
pp. 3-10
Author(s):  
Zhi Chen Yu ◽  
Zhen Li Mi ◽  
Qing Wu Cai ◽  
Jin Guo ◽  
Na Gong
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Microalloyed Steel ◽  
Ferrite Matrix ◽  
Precipitation Behavior ◽  
Rapid Cooling ◽  
Cooling Temperature ◽  
Interphase Precipitation ◽  
Transmission Electron ◽  
Scanning Electron

The size and distribution of nanoscale precipitate particles in Ti-Mo ferrite matrix microalloyed steel under three different final rapid cooling temperatures were studied by scanning electron microscopy(SEM), transmission electron microscope(TEM) and microhardness test. The results show that the interphase precipitation could be weakened by the excessive final rapid cooling temperature. A higher supersaturated solid solubility and high-density dislocation in ferrite matrix can be obtained under a relatively lower final rapid cooling temperature, which makes it easier to precipitate in ferrite. The related thermodynamic analysis indicated that the precipitation behavior was influenced by the final rapid cooling temperature during austenite/ferrite region. It is not conducive to get a large amount of small size precipitates in Ti-Mo ferrite matrix microalloyed steel when the final rapid cooling temperature is too high or low.

Thermal Relaxation Process of Stearate LB Films Sandwiched by Chromophoric Polymer LB Layers Studied by the Energy Transfer Method and Transmission Electron Microscopy

Langmuir ◽  
1994 ◽  
Vol 10 (11) ◽  
pp. 4142-4147 ◽  
Author(s):  
Takanori Hayashi ◽  
Shinzaburo Ito ◽  
Masahide Yamamoto ◽  
Yoshinobu Tsujii ◽  
Mutsuo Matsumoto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Transfer ◽  
Relaxation Process ◽  
Thermal Relaxation ◽  
Lb Films ◽  
Transmission Electron ◽  
Transfer Method

Variation of the Reversed Austenite Amount with the Tempering Temperature in a Fe-13%Cr-4%Ni-Mo Martensitic Stainless Steel

2010 ◽  
Vol 650 ◽  
pp. 193-198 ◽  
Author(s):  
Yuan Yuan Song ◽  
Xiu Yan Li ◽  
Fu Xing Yin ◽  
De Hai Ping ◽  
Li Jian Rong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
Martensitic Stainless Steel ◽  
Low Carbon ◽  
Reversed Austenite ◽  
X Ray Diffraction ◽  
Tempering Temperature ◽  
X Ray ◽  
Transmission Electron

Tempering temperature dependence of the amount of the reversed austenite in the range of 570 oC to 680 oC was investigated by means of X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM) in a low carbon Fe-13%Cr-4%Ni-Mo (wt.%) martensitic stainless steel. It was found that the reversed austenite began to form at the tempered temperature slightly above the As temperature. As the tempered temperature increased, the amount of the reversed austenite changed little in the temperature range of 580-595 oC. Then, the amount of the reversed austenite increased sharply with the increased tempered temperature. When the tempered temperature increased to about 620 oC, the amount of the reversed austenite exhibited a peak. Afterward, it decreased quickly at the elevated tempered temperature. The microstructural evolvement of the reversed austenite at different tempering temperature was also observed by TEM.

Influence of Coiling on Microstructural Evolution and Mechanical Properties of Strip-Cast Low-Carbon Low-Niobium Steel

2016 ◽  
Vol 879 ◽  
pp. 1182-1187 ◽  
Author(s):  
Lu Jiang ◽  
Thomas Dorin ◽  
Ross Marceau ◽  
Nicole Stanford ◽  
Peter Hodgson
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Microstructural Evolution ◽  
Strong Influence ◽  
Low Carbon ◽  
Strengthening Mechanisms ◽  
Transmission Electron ◽  
Final Microstructure ◽  
Strip Cast

As-cast low-carbon low-niobium steels fabricated by direct strip casting (DSC) were treated by simulated coiling in the lab. Coiling temperatures were carefully selected: (1) 900 ̊C (in the austenite); (2) 700 ̊C (during the austenite-to-ferrite transformation); (3) 650 ̊C (in the ferrite). Optical microscopy and transmission electron microscopy were used to examine the microstructure constituents and the precipitates. Mechanical properties were evaluated by Vickers macrohardness measurements. The results show that coiling treatment has a strong influence on the final microstructure and mechanical properties, thus highlighting the necessity to carefully design the coiling treatment. In addition, the differences in hardness for the three coiling temperatures derive from a complex combination of different strengthening mechanisms.

Effect of Boron and Titanium Addition on the Hot Ductility of Low-Carbon Nb-Containing Steel

2015 ◽  
Vol 34 (8) ◽  
Author(s):  
Wei-Jian Liu ◽  
Jing Li ◽  
Cheng-Bin Shi ◽  
Xiang-Dong Huo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Tensile Tests ◽  
Hot Ductility ◽  
Low Carbon ◽  
Titanium Addition ◽  
Intragranular Ferrite ◽  
Transmission Electron ◽  
Scanning Electron

AbstractThe effect of boron and titanium addition on the hot ductility of Nb-containing steel was investigated using hot tensile tests. The fracture surface and the quenched longitudinal microstructure were examined by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that both steel samples had the similar change from 1,100°C to 700°C. The hot ductility of Nb-containing steel with boron and titanium addition was higher than the steel without boron and titanium in the temperature range of 900–750°C. Because the formation of intergranular ferrite was inhibited by solute boron segregating on the grain boundary, the formation of TiN changed the distribution of Nb- and boron-containing precipitates and improved the amount of intragranular ferrite.

Investigation on Dissolving and Strain Induced Precipitation Behavior in Nb-Bearing Microalloyed Steel

2011 ◽  
Vol 109 ◽  
pp. 3-6
Author(s):  
Shao Qiang Yuan ◽  
Guo Li Liang ◽  
Hui Bin Wu
Keyword(s):  
Relaxation Time ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Microalloyed Steel ◽  
Thermal Simulation ◽  
Holding Time ◽  
The Other ◽  
Precipitation Behavior ◽  
Simulation Test ◽  
Transmission Electron

Thermal simulation test, TEM(Transmission Electron Microscope) and nanobeam EDS techniques were used to investigate the dissolving and precipitation behavior in Nb-bearing mciroalloyed steel. The experimental results indicate that: there are two families of precipitates in the as forged samples. The larger precipitates of Nb(C,N) disappear after being held for 2h at 1300°C,while the inclusions of MnS formed from the solidification even remain for 48h held at that temperature. After 30% of predeformtion at 850°C and 900°C, the strain-induced precipitation occurs, that is, the other tiny precipitates. Compared with the samples relaxed at 850°C, the ones that are held at 900°C show larger particles by same holding time but demonstrate the same size when the relaxation time reaches 1000s.

Microstructures after Processing by Aging and ECAP for Al-Mg2Si Alloys Containing Excess Si or Mg

2005 ◽  
Vol 475-479 ◽  
pp. 4047-4050 ◽  
Author(s):  
Kazuko Fujita ◽  
Takeshi Fujita ◽  
Keiichiro Oh-ishi ◽  
Kenji Kaneko ◽  
Z. Horita ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Binary System ◽  
Equal Channel Angular Pressing ◽  
Precipitation Behavior ◽  
Angular Pressing ◽  
Transmission Electron

In this study, severe plastic straining through equal-channel angular pressing (ECAP) is imposed on age-hardenable Al-Mg-Si alloys having two different compositions of excess Si or Mg in the Al-Mg2Si pusedo-binary system. Thereafter, the alloys are subjected to aging and the microstructures are examined using transmission electron microscopy. It is shown that the precipitation behavior is significantly changed through application of ECAP.

Sign in / Sign up

Export Citation Format

Share Document