Fuzzy recognition of graphite morphology in nodular cast iron based on evolution strategy

Author(s):  
Chen Zhibin ◽  
Yu Yongquan ◽  
Chen Heqing ◽  
Yang Shaomin
2021 ◽  
Author(s):  
Joona Vaara ◽  
Miikka Väntänen ◽  
Jarkko Laine ◽  
Jukka Kemppainen ◽  
Tero Frondelius

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 311
Author(s):  
Christian Gebhardt ◽  
Johannes Nellessen ◽  
Andreas Bührig-Polaczek ◽  
Christoph Broeckmann

The fatigue strength of high silicon-alloyed nodular cast iron is influenced by casting defects and graphite precipitates. The literature as well as the findings of this work show that these microstructural constituents can be tailored by controlling silicon microsegregation. In addition, segregations also affect the ferritic matrix microstructure locally. In the present work, silicon segregations in high silicon-alloyed ductile iron are specifically manipulated by small additions of aluminum. It was demonstrated how the aluminum content affects a wide range of microstructural constituents across a variety of length scales. Specimens from alloys with small additions of aluminum were fabricated and tested by rotating bending. Results show that the fatigue strength can be increased compared to a reference alloy with no aluminum. Microstructure analysis as well as fractography were performed concluding that microstructural changes could be attributed to the increased aluminum content, which allows the fatigue properties to be tailored deliberately. However, according to the results of this study, the negative effect of aluminum on castability and graphite morphology limits the maximum content to approximately 0.2 wt.%.


2006 ◽  
Vol 324-325 ◽  
pp. 851-854
Author(s):  
Jin Hai Liu ◽  
Xiao Yan Hao ◽  
Guo Lu Li ◽  
Xue Bo Zhao ◽  
Gen Sheng Liu

The influence of fatigue ratio on the low cycle fatigue damage of nodular cast iron was investigated by measuring the elastic modulus. The results indicated that the elastic modulus of nodular cast iron is a sensitive parameter to the fatigue damage at low cycle. The fatigue damage variable of nodular cast iron increases with cycle ratio. At the beginning and end period of cycling, the damage of nodular iron increases sharply, and in the range of 0.2- 0.8 cycle ratio, the fatigue damage grows gradually.


2010 ◽  
Vol 97-101 ◽  
pp. 2205-2208 ◽  
Author(s):  
Xia Zhou ◽  
Guo Hui Qu

The aim of this paper is to explore the possibility of a novel surface technique for Fe-based amorphous and micro-nano composite coatings. A kind of iron based amorphous and micro/nano-crystalline alloy powder which contains Fe, Ni, Cr, W, Mo, B, Si, C etc. was first prepared by mechanical alloying method. Iron based amorphous alloy coatings were then deposited on nodular cast iron substrate by electro-spark deposition using electrode materials with the ball-milling iron based alloy and SiC mixed powders. Annealing crystallization treatment of the Fe-based amorphous alloy coatings was conducted at last. The microstructure and surface morphology of the coating were analyzed by optical microscopy (OM) and scanning electron microscopy (SEM), the amorphous and crystal configuration were confirmed with an X-ray diffractometer (XRD), the microhardness was measured with a micro-sclerometer. The experimental results show that the Fe-based composite coatings are composed of Fe-based amorphous alloy matrix and dispersion strengthened micro- and nanocrystalline particles. The coatings of about 60 m in thickness are uniform, dense and metallurgically bonded to the substrate with high microhardness of about 880 (HV100, 15 S), implying a much improved wear resistance on surface of cast iron.


2014 ◽  
Vol 82 ◽  
pp. 378-390 ◽  
Author(s):  
F.D. Carazo ◽  
S.M. Giusti ◽  
A.D. Boccardo ◽  
L.A. Godoy

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