Microstructure and abrasive wear resistance of an alloyed ductile iron subjected to deep cryogenic and austempering treatments
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2017年第12期
论文作者：Junjun Cui Liqing Chen
文章页码：1549 - 1554
摘 要：To further improve the mechanical performance of a new alloyed austempered ductile iron（ADI）, deep cryogenic treatment（DCT） has been adopted to investigate the effect of DCT time on the microstructure and mechanical behaviors of the alloyed ADI Fe-3.55 C-1.97 Si-3.79 Ni-0.71 Cu-0.92 Mo-0.64 Cr-0.36 Mn-0.30 V（in wt.%）. With increasing the DCT time, more austenite transformed to martensite and very fine carbides precipitated in martensite in the extended period of DCT. The amount of austenite decreased in alloyed ductile irons, while that of martensite and carbide precipitation increased. The alloyed ADI after DCT for 6 h had the highest hardness and compressive strength, which can be attributed to the formation of more plate-like martensite and the finely precipitated carbides. There was a gradual decrease in hardness and compressive strength with increasing the DCT time to 12 h because of the dissolution of M3 C carbide. After tempering, there was a decrease in mechanical properties compared to the direct DCT sample, which was caused by the occurrence of Ostwald ripening of precipitated carbides. The optimum wear resistance was achieved for the alloyed ADI after DCT for 6 h. The wear mechanism of the alloyed ADI in associating with DCT is mainly consisted of micro-cutting wear and some plastic deformation wear.
Junjun Cui1,2，Liqing Chen1
1. State Key Laboratory of Rolling and Automation, Northeastern University2. College of Mechanical and Vehicle Engineering, Shenyang Institute of Technology
摘 要：To further improve the mechanical performance of a new alloyed austempered ductile iron（ADI）, deep cryogenic treatment（DCT） has been adopted to investigate the effect of DCT time on the microstructure and mechanical behaviors of the alloyed ADI Fe-3.55 C-1.97 Si-3.79 Ni-0.71 Cu-0.92 Mo-0.64 Cr-0.36 Mn-0.30 V（in wt.%）. With increasing the DCT time, more austenite transformed to martensite and very fine carbides precipitated in martensite in the extended period of DCT. The amount of austenite decreased in alloyed ductile irons, while that of martensite and carbide precipitation increased. The alloyed ADI after DCT for 6 h had the highest hardness and compressive strength, which can be attributed to the formation of more plate-like martensite and the finely precipitated carbides. There was a gradual decrease in hardness and compressive strength with increasing the DCT time to 12 h because of the dissolution of M3 C carbide. After tempering, there was a decrease in mechanical properties compared to the direct DCT sample, which was caused by the occurrence of Ostwald ripening of precipitated carbides. The optimum wear resistance was achieved for the alloyed ADI after DCT for 6 h. The wear mechanism of the alloyed ADI in associating with DCT is mainly consisted of micro-cutting wear and some plastic deformation wear.
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