Entity

Time filter

Source Type


Li J.-W.,Henan University of Science and Technology | Zhang G.,Henan University of Science and Technology | Wei S.,Henan Engineering Research Center for Wear Resistance Materials
Advanced Materials Research | Year: 2011

A new wear resistance material named the hypoeutectic high carbon Fe-B cast steel with fine hard carbides dispersive distributed in the matrix have been investigated. The results show that the solidified structures of high carbon Fe-B steel consist of ferrite, pearlite and boride, and borides were distributed along grain boundary in interconnected network. After heat treatment, the metallic matrix changes into martensite and retained austenite. The eutectic borides are appeared to be less continuous network and isolated particles. The increasing of the quenching temperature leads to the improvement of hardness. Quenching at 980°C, impact toughness is increased with the increasing of the tempering temperature. The optimum heat treatment is quenching at 980°C(oil cooling) and tempering at 330°C(air cooling). The wear resistance of modified high carbon Fe-B cast steel is corresponding to Cr26 alloy. The impact wear mechanism is mainly plastic deformation and fatigue spalling.


Li J.-W.,Henan University of Science and Technology | Li J.-W.,Henan Engineering Research Center for Wear Resistance Materials | Wang A.-Q.,Henan University of Science and Technology | Xie J.-P.,Henan University of Science and Technology | And 2 more authors.
Materials Science Forum | Year: 2010

Rapidly solidified hypereutectic Al-21Si was prepared by the single roller melt-spinning technique. The microstructure morphology characteristics and phase structures of the alloy were characterized using SEM, TEM and XRD technique. The results showed that the grains were refined and the micro-nano composite structures were formed under rapid solidification. The microstructure of the Al-21Si alloy was composed of micro-nanostructured α-Al phase and feather-needle-like eutectic α-Al+β-Si phase. The α-Al phase was the leading phase in the eutectic α+Si phase. The nucleation and growth of primary silicon are suppressed and primary silicon could not be precipitated. The hypereutectic Al-21Si alloy showed the hypoeutectic solidification microstructure. Wear resistance was improved obviously when the rapidly solidified and was five times higher than that of the traditional casting alloys. © (2010) Trans Tech Publications.


Zhao Y.-R.,CITIC Heavy Industries Co. | Li J.-W.,Henan University of Science and Technology | Zhang G.-S.,Henan University of Science and Technology | Wei S.-Z.,Henan Engineering Research Center for Wear Resistance Materials
Zhuzao/Foundry | Year: 2011

The influence of RE modifier and heat treatment on microstructure and properties of the hypereutectic high carbon Fe-C-B steel was investigated. The results show that the solidified microstructure of the hypereutectic high carbon Fe-C-B steel is composed of the α-Fe phase, primary Fe 2B phase and eutectic Fe 3(C, B) phase. The primary Fe 2B phases are visibly refined after modified with RE element. With the increasing of RE addition, the size of the primary Fe 2B phases is decreased. Meanwhile, the morphologies of the eutectic boride are changed from rosette-shaped to the graininess. After heat treatment, the eutectic boride changes substantively. Some of the eutectic Fe 3(C, B) phases transformed to Fe 3B phases after 970°C oil quenching. However, after the 1050°C oil quenching, all of the eutectic Fe 3(C, B) phases are disappeared and transformed to Fe 2B phases. The hypereutectic high carbon Fe-C-B steel shows excellent mechanical properties after RE modification and heat treatment, and the wear resistance is corresponding to the high chromium cast iron.


Li J.-W.,Henan University of Science and Technology | Li J.-W.,Henan Engineering Research Center for Wear Resistance Materials | Wang A.-Q.,Henan University of Science and Technology | Xie J.-P.,Henan University of Science and Technology | And 4 more authors.
Mocaxue Xuebao/Tribology | Year: 2010

Rapidly solidified hypereutectic Al-21Si and Al-30Si alloys were prepared by a single roller melt-spinning technique. The microstructure and phases of the alloys were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Fine grains with a micro-nano composite microstructure were obtained by rapid solidification. The microstructures of the Al-21Si alloys were characterized by primary micro-nanostructured α-Al phase and feather-needle-like α-Al+β-Si eutectic. The nucleation and growth of primary silicon were effectively inhibited. α-Al phase had a higher priority to nuclate and grow than eutectic α+Si phase. The hypereutectic Al-21Si alloy showed the hypoeutectic microstructure. The primary Si phases in Al-30Si alloy were fine twins. And this microstructures were a typical hypereutectic microstructure. Microhardness and wear resistance (i.e. 5 times as high as that of traditional casting alloys) of alloys were greatly improved by rapidly solidification.


Li J.-W.,Henan University of Science and Technology | Li J.-W.,Henan Engineering Research Center for Wear Resistance Materials | Zhang G.-S.,Henan University of Science and Technology | Wei S.-Z.,Henan University of Science and Technology | And 2 more authors.
Zhuzao/Foundry | Year: 2010

The wear-resistance plate hammers are successfully made by means of the bimetal liquid-liquid composite technologies. The innovative point is that the liquid metal was poured by three times, the high chromium cast iron first, low alloy steel second and the high chromium cast iron once more. The key technologies to achieve the metallurgical bonding on the interface are the reasonable casting technological design, the proper interface protection measures and the controllable pouring interval. The bimetal plate hammers can obtain the good match of mechanical properties by means of the reasonable heat treatment process.

Discover hidden collaborations