ADI之Al2O3顆粒高速沖蝕誘發相變態

Phase Transformation of ADI Induced by Al2O3 Particle Erosion

10.29809/JTFS.200706.0004

洪飛義(F. Y. Hung)；呂傳盛(T. S. Lui)；陳立輝(L. H. Chen)

沖蝕 ； ADI ； 相變態 ； ε-碳化物 ； erosion ； austempered ductile cast iron ADI ； phase transformation ； ε-carbide

鑄造工程學刊

33卷2期（2007 / 06 / 01）

40 - 46

繁體中文

本研究以C含量約為3.5 wt.%而Si含量約為2.8 wt.%之上變韌體基沃斯回火球墨鑄鐵為實驗材料，其熱處理條件是於420℃進行0.5hr~24 hr的恆溫沃斯回火。實驗選擇平均粒徑約在275μm之Al2O3為沖蝕顆粒且其顆粒之沖蝕速度約為73m sec^(-1)，藉以檢討ADI試料在正向900沖蝕後之磨耗表面組織相變態行為。實驗結果顯示，ADI試料中的殘留沃斯田體相體積率及高碳變韌肥粒體相之碳含量會因沖蝕誘發相變態而減少。ADI試料經顆粒沖蝕後，殘留沃斯田體相及變韌肥粒體相會誘發生成ε-碳化物、其他碳化物與肥粒體。此外，基地中其他回火析出碳化物也會因沖蝕過程進一步相變態形成ε-碳化物。

A ductile iron of ~3.5 wt.% C and ~2.8 wt.% Si was austempered at 420℃ for 0.5hr~24 hr. These upper bainitic austempered ductile iron (ADI) specimens were 900-eroded to understand the phase transformation on the erosion surface by Al2O3 particles of ~275μm grit size under the average particle velocity of 73 m sec-1. According to the experimental results, the content of the retained austenite and the carbon content of bainitic ferrite will decrease by eroded phase transformation. After erosion, both of the retained austenite and bainitic ferrite will form the ε-carbide, other carbide and ferrite. Beside, the other austempering carbide of remaining matrix will also transform to ε-carbide in the erosion process.