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Shi C.,National Science Foundation | Zhong Z.,The Chinese Society for Metals
Jinshu Xuebao/Acta Metallurgica Sinica | Year: 2010

In this paper the development course of superally in China, The technical progress and innovation in recent years and works in the future are described.


Tan Z.-L.,Beijing Jiaotong University | Wang K.-K.,Beijing Jiaotong University | Gao G.-H.,Beijing Jiaotong University | Gui X.-L.,Beijing Jiaotong University | And 3 more authors.
Journal of Iron and Steel Research International | Year: 2014

Quenching-partitioning-tempering (Q-P-T) process were applied to a quenched carbide-free bainite/martensite (CFB/M) multiphase steel 40Mn2Si2Cr and its effect on the mechanical properties was studied. The results showed that the partitioning time of Q-P-T treatment can be increased greatly to 90 min or even longer. The tensile strength, elongation and product of strength and elongation (PSE) of the experimental steel can achieve 1650 MPa, about 20% and over 33 GPa · %, respectively. The significant increase of partitioning time and excellent mechanical properties could be related to the CFB microstructure introduced in the quenching process during the Q-P-T treatment. © 2014 Central Iron and Steel Research Institute.


Wang Z.,Tsinghua University | Wang Z.,Control Iron and Steel Research Institute, China | Sun X.,Control Iron and Steel Research Institute, China | Yang Z.,Tsinghua University | And 4 more authors.
Materials Science and Engineering A | Year: 2013

The carbide precipitation behavior in austenite of a 0.04%C-0.10%Ti-0.21% Mo micro-alloyed steel was investigated by the stress relaxation method and transmission electron microscopy. Results showed that the precipitation-time-temperature diagram for carbide precipitation exhibited a typical "C" curve, the nose of which was located at about 925 °C. The carbide was identified as a (Ti, Mo)C particle with a NaCl-type crystal structure that contains a certain amount of Mo. As compared with TiC particle in Ti steel, (Ti, Mo)C particle in Ti-Mo steel exhibits a superior coarsening resistance during the coarsening stage. The fraction of Mo in (Ti, Mo)C particle decreases with isothermal holding time or particle growing, indicating that the high level replacement of Ti by Mo in TiC lattice is in a "metastable" state with respect to the equilibrium precipitation of (Ti, Mo)C in austenite. © 2013 Elsevier B.V.


Liu W.,Tsinghua University | Zhang C.,Tsinghua University | Yang Z.,Tsinghua University | Xia Z.,Suzhou Nuclear Power Research Institute | And 2 more authors.
Jinshu Xuebao/Acta Metallurgica Sinica | Year: 2013

Nanocrystalline grains in the surface of reduced activation ferrite/martensite (RAFM) steel were produced by means of surface mechanical attrition treatment (SMAT). Analysis results of XRD and TEM showed that grains after SMAT were nanocrystalline. Experiment results after annealing at 550°C showed that the nanocrystallines were stable. Abnormal grain growth was observed from the TEM images after tempered for 120 min, and the grain sizes became uniform after tempered for 240 min (about 250 nm). The XRD diffraction peaks of carbides became weaker and boarder indicated that carbides in the surface layer became smaller after SMAT, and smaller MC type carbides were found from HRTEM images after SMAT. The lattice parameters of M23C6 and MC were 1.0631 and 0.4306 nm calculated from the XRD results. The differences of grain sizes obtained by XRD and TEM could be attributed to the different testing mechanism, different measuring depths and the depth-dependent nanocrystalline microstructure, and results obtained by TEM were more accurate to reveal the real grain size. © Copyright.


Wang Z.,Tsinghua University | Wang Z.,Control Iron and Steel Research Institute, China | Mao X.,Guangzhou Zhujiang Steel Co. | Yang Z.,Tsinghua University | And 5 more authors.
Materials Science and Engineering A | Year: 2011

The strain-induced precipitation kinetics of TiC in a 0.05% C-0.10% Ti HSLA steel was investigated by two-stage interrupted compression method. The precipitation-time-temperature (PTT) diagram for TiC precipitation was obtained by analyzing the softening kinetics curves of deformed austenite, which was confirmed to be of validity by employing transmission electron microscopy (TEM). Experimental results showed that the PTT diagram for TiC precipitation exhibited a typical "C" shaped and the nucleation of strain-induced TiC precipitation was a very rapid process in the temperature range 900-925 °C. The relatively severe deformation applied on the steel was considered to be the main factor resulting in the fast kinetics of TiC precipitation. The TiC precipitates were heterogeneously distributed in either a chain-like or a cell like manner, implying that the precipitates nucleated on dislocations or on dislocation sub-structures, which were produced by deformation. The growth of TiC precipitates approximately followed a parabolic law. In addition, the coarsening of strain-induced TiC precipitates had already started before the completion of precipitation. © 2011 Elsevier B.V.


Weng Y.-Q.,The Chinese Society for Metals | Yang C.-F.,Control Iron and Steel Research Institute, China | Shang C.-J.,University of Science and Technology Beijing
Kang T'ieh/Iron and Steel (Peking) | Year: 2011

During the last decade, the adjustment of product segments always is a very important task of iron industry, and upgrading of steel products has being impelled actively by Chinese iron and steel industry. With rapidly increasing of iron and steel production, a series of research achievements have been made in the technology area of high strength low alloy (HSLA) steel, and also have been applied successfully in the actual production, e.g. the technology of fine grain and ultra-fine grain steels, the technology for the control of microalloying precipitates. It is an important strategic goal of "Twelfth Five-Year Plan" for Chinese iron and steel industry that the adjustment of steel product segments and meeting the requirements for upgrading of domestic and oversea equipment manufactory industry. Adopting HSLA steel with better performance, instead of plain steel, could save steel consumption largely, and also release pressures from resource, energy and environment. Without doubt, it is the only way to realize the sustained development of Chinese iron and steel industry by popularizing the application of HSLA steels vigorously.


Weng Y.-Q.,The Chinese Society for Metals | Kang Y.-L.,University of Science and Technology Beijing
Kang T'ieh/Iron and Steel (Peking) | Year: 2010

Resent progress in steel rolling technology in China was briefly introduced in present work, including: technology integration and development of production lines, such as hot wide strip, wide and heavy plate, large-scale cold continuous rolling and three roll continuous pipe-rolling mill, as well as the equipment modernization development of thin slab casting and rolling line; progress in steel rolling technologies such as semi-endless rolling, thin strip production, long length (100m) rail rolling and new generation controlled cooling technology; research and application of microstructure-property control during the rolling process, and the development of production technology and steel grades including high performance and high strength strip, medium heavy plate, cold rolling strip, long products and tubes; development of energy-saving and emission-reduction technology, such as the non-oxidizing or low oxidizing heat equipment and technology.


Lang Y.-P.,Control Iron and Steel Research Institute, China | Chen H.-T.,Control Iron and Steel Research Institute, China | Weng Y.-Q.,The Chinese Society for Metals | Qu H.-P.,Control Iron and Steel Research Institute, China
Cailiao Gongcheng/Journal of Materials Engineering | Year: 2013

The Thermo-Calc software was used to calculate the influence of pressure factor and elements including C, Cr, Mn and Ni on the solubility of nitrogen, the phase transformation during solidification in high nitrogen austenitic stainless steel with 22%(mass fraction) Cr. The microstructures and precipitates of new designed high austenitic stainless steel were studied also. The results show that Cr increases mainly the solubility of nitrogen in liquid steel. With about 0.1%C the minimum solubility of nitrogen during higher solidification temperature is enhanced remarkably. Mn increases not only the solubility of nitrogen in liquid steel but also the minimum solubility of nitrogen during earlier solidification. With proper Mn the phase area of austenite is extended and more stably, also the "ferrite trap" can be avoided. With a little nickel less than 2% the minimum solubility of nitrogen during higher solidification temperature is enhanced and the temperature extension of δ phase presence is reduced, also to make sure full austenite in steel at room temperature. Melting under pressure is efficiently to increase the solubility of nitrogen. The main precipitates of new high austenitic stainless steel are Cr23C6 and Cr2N. To use thermodynamic calculation tools can be beneficial to research the melting, structure, heat treatment and hot working of high nitrogen austenitic stainless steels.


Chen Q.-A.,Control Iron and Steel Research Institute, China | Che Y.-M.,The Chinese Society for Metals | Zhe Q.-Y.,Xi'an University of Architecture and Technology
Kang T'ieh/Iron and Steel | Year: 2012

The strategy discussion on the updating of ribbed bar and related resource problem was necessary based on its massive production. In point of view of extreme resource utilization, the outstanding local difference in China and the limited sales radius of ribbed bar brought the multi-purpose and local preparing technique to the ribbed bar updating and then the local standard was recommended. The concept of alternating strain base design should be introduced in the ribbed bar updating to ensure the anti-seismic properties of rebar. The resent (Q235+Mn) and (Q235+Mn+MA) strengthening pattern had the shortage of the resource and the welding jointing should not utilize the resource full. It was recommended to develop the (Q235+C) strengthening pattern for the mechanical jointing of rebar in order to get better effect of resource utilization. The preliminary lab result was given.


Dong P.-L.,The Chinese Society for Metals
Kang T'ieh/Iron and Steel | Year: 2016

To investigate the suitable bottom blowing process, the influence of different positions of bottom blowing hole on the mixing time and surface wave was studied. Based on the similarity principle, a physical modeling system was built for the bottom blowing argon process in a 210 t ladle. By studying the influence of different positions and angles of bottom blowing hole on the mixing time and surface wave, the optimal bottom blowing process was determined. The results show that the optimal bottom blowing hole was located at 0.60R/0.60R and the angle was 100°. When the location of bottom blowing holes was lied in 0.40R, the two columns interacted on each other. 0.60R for the location of bottom blowing holes was the ideal place. The erosion of airflow on the wall was serious when the location of bottom blowing holes placed at 0.79R. © 2016, CISRI Boyuan Publishing Co., Ltd. All right reserved.

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