scholarly journals Effects of Heat-Treatment on the Microstructure and Wear Resistance of a High-Chromium Cast Iron for Rolls

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Zhi-hong Guo ◽  
Fu-ren Xiao ◽  
Su-ling Lu ◽  
Han-yun Li ◽  
Bo Liao

The variations of microstructure and mechanical properties of a high-chromium cast iron for rolls were studied from as-cast to the final heat treatments. Results show that the as-cast microstructure of the HCCI consists of M7C3carbide, M23C6carbide, martensite matrix, and retained austenite. The large dendritic M7C3carbide surrounds the matrix, and the M23C6carbide is mainly distributed in the matrix. Part of M23C6carbide transforms to M7C3carbide and is dissolved in austenite during austenization at 1020°C. Thus, the amount of M23C6carbide decreases, whereas that of M7C3carbide increases after quenching; the highest hardness is also obtained. After tempering, the martensite transforms to a tempered martensite, and some carbide precipitates in the martensite matrix. The hardness also changes from HRC62.1, which corresponds to quenching, to HRC55.2 and HRC56.3, which correspond to once and twice tempering, respectively. However, tempering could improve the impact toughness and wear resistance of the HCCI.

2016 ◽  
Vol 25 (41) ◽  
pp. 93 ◽  
Author(s):  
Oscar Fabián Higuera-Cobos ◽  
Florina-Diana Dumitru ◽  
Dairo Hernán Mesa-Grajales

<p>High-Chromium White Cast Iron is a material highly used in mining and drilling shafts for oil extraction, due to its high wear resistance. However, because of the austenitic matrix found in the as-cast state, an adequate heat treatment cycle is necessary. This paper studies the effects of different cooling media after a destabilization treatment on the microstructure, hardening and abrasion resistance behaviors of a hypoeutectic high chromium white cast iron. The results show that although air cooling followed by immersion in CO2 can effectively reduce the retained austenite, this is not enough to transform completely the retained austenite into martensite. The low retained austenite percentages improve bulk hardness, but they decrease the abrasion resistance of the high chromium cast iron. The best combination of hardness and wear resistance was found in the samples cooled in air, due to the percentage of retained austenite and a moderate precipitation of chromium carbide.</p>


2011 ◽  
Vol 179-180 ◽  
pp. 1338-1341
Author(s):  
Jiang Liu ◽  
Jun Fu

Because of high wear resistance and low cost, high chromium cast iron liner plate is the most commonly used liner for HZS series concrete mixing station at present. However, in normal operation, the high-chromium cast iron liner produced by conventional casting process is easy to crack at its corners. We found that the cracking reasons of this type of liner plate are mainly the lower cast impact toughness, slightly higher hardness, and there has not gotten a good matching between the hard particles and the matrix organizations. Thus we used the secondary heat treatment to slightly reduce the hardness and increase the impact toughness of cast iron liner plate, which can improve the wear resistance and impact resistance of the liner material to extend the service life of these cast iron liners.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 490
Author(s):  
Annalisa Fortini ◽  
Alessio Suman ◽  
Alessandro Vulpio ◽  
Mattia Merlin ◽  
Michele Pinelli

Surface material loss due to erosive wear is responsible for the increased cost of maintenance and downtime in industries. Hence, hardfacing is one of the most valuable and effective techniques employed to improve the wear resistance of heavy-duty components. The present paper investigates the microstructural and erosive wear characteristics of a hypereutectic high-chromium cast iron, considering the erosion resistance, resulting from the impact of micro-sized particles, of both as-received and heat-treated conditions. Micro-sized particles involve the erosion-resistant characteristics of carbide and matrix, contemporary. Due to this, the enhancement of the matrix strength could improve the mechanical support to withstand cracking deformation and spalling. Accordingly, the effect of a destabilization heat treatment on the microstructure was firstly investigated by hardness tests, X-ray diffraction analyses, optical and scanning electron microscopy. Specifically designed erosive tests were carried out using a raw meal powder at an impingement angle of 90°. The resulting superior wear resistance of the heat-treated samples was relayed on the improved matrix microstructure: consistent with the observed eroded surfaces, the reduced matrix/carbides hardness difference of the heat-treated material is pivotal in enhancing the erosion resistance of the hardfacing. The present results contribute to a better understanding of the microstructure–property relationships concerning the erosive wear resistance.


Wear ◽  
1990 ◽  
Vol 135 (2) ◽  
pp. 217-226 ◽  
Author(s):  
Tong Jian-Min ◽  
Zhou Yi-Zhong ◽  
Shen Tian-Yi ◽  
Deng Hai-Jin

2012 ◽  
Vol 217-219 ◽  
pp. 2410-2413 ◽  
Author(s):  
Xing Hai Shao ◽  
Jing Pei Xie ◽  
Wen Yan Wang ◽  
Yan Li ◽  
Pin Gan Zhou ◽  
...  

The effects and the mechanisms of namo TiN on the high chromium cast iron are studied, the material has been prepared through infiltration casting and addition of high carbon ferrochrome powder and nano TiN powder. The alloy is formed on the surfaced of guide plate, and the wear resistance of alloy have been studied by means of SEM, XRD micro-analysis and wear-resistant performance. The grain size and the type of carbide in the organization are affected by nano TiN, and the wear resistance of carbon chromium alloy layer is affected by the type of carbide; when the addition of nano TiN is 1% (wt), the grain size is apparently refined, overeutectic primary M7C3 in the hypereutectic is precipitated uniformly in considerable amounts, therefore the wear resistance of alloy can be improved effectively.


2010 ◽  
Vol 51 (7) ◽  
pp. 1264-1271 ◽  
Author(s):  
Sudsakorn Inthidech ◽  
Khatawut Boonmak ◽  
Prasonk Sricharoenchai ◽  
Nobuya Sasaguri ◽  
Yasuhiro Matsubara

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