Speaker
Description
Research shows that the wear phenomenon has a ruinous impact on the world's energy expenditure which consumes 23% of the world’s energy. Abrasion wear is a material loss process during which the material's surface is eliminated or destroyed. This incident has caused a significant problem for the crushing blade of crushing shredder, in steel mills and mining. In this age, a noticeable number of machines and equipment are operated in high temperatures hence high temperature abrasion. Abrasive wear behaviors of stainless steels at high-temperature conditions are investigated by researchers. It is found that at high temperatures, the abrasion rate is high for materials such as iron and steel. According to the previous study, the decrease in hardness at high temperatures is considered one of the main causes of the high abrasion rate. As the manufacturing of commercial tools with superior wear resistance is an enormous need, this present research focuses on the high temperature abrasive wear characteristics of high-chromium white cast irons with different carbon percentages (3 and 3.5% of C).
Summary
According to the performed experiments, it is observed that the higher percentage of C content with a high Cr white cast irons has a significant impact on influencing the carbide precipitation, carbide, hardness. The microstructural observation of the specimens illustrates that with the increase of C content the number of precipitated carbides (M7C3) begins to appear in bigger size. It can be concluded that the carbide volume fraction increases with the increase of C content. The hardness result at (900℃) shows that the specimens with higher C content exhibit slightly higher hardness. It seems that the higher volume fraction of carbide (CVF) plays a vital role to elevated hardness value. The high temperature abrasive wear data shows that the specimen (3C-27HCCI) with the lowest C content exhibits the highest wear rate when the wear rate decreases for 3.5C-27HCCI. It can be assumed that the higher hardness and higher carbide volume fraction leads to lower wear rate. The cross-sectional observation of the 3C-27HCCI specimen demonstrates an abundance of fractured carbides and plastic deformation. However, this phenomenon starts to decrease with the increase of C content. For 3.5C-27HCCI fractured carbides and plastic deformation are hardly seen. After performing the high temperature abrasive wear test on 3C-27HCCI and 3.5C-27HCCI and observation through various means, the conclusion can be made as below.
1.The increase of C to HCCI helps to precipitate a higher percentage of hard M7C3 carbides.
2. Higher Carbide volume fraction (CVF) and hardness is observed in specimens with higher C content.
3. Among 3C-27HCCI and 3.5C-27HCCI specimens the 3.5C-27HCCI shows higher wear resistance.
4.The wear mechanism can be explained as the abrasion wheel hits the softer, lower hardness and lower carbides contained matrix of 3C-27HCCI that leads to higher abrasion rate. However, for 3.5C-27HCCI the harder and higher number of carbides withstand the hit of the abrasion wheel hence lower the abrasive wear rate.
| Speaker Country | Japan |
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