【摘要】 8407钢是常用的铝合金压铸用模具钢.为改善模具的抗热疲劳和抗熔损性能,对冷喷涂Al后的8407钢试样在500,550℃下进行扩散处理,渗铝后的试样在纯O2气氛,570℃的条件下进行氧化,渗层表面形成了Fe-Al-O的混合氧化物.考察了扩散温度和扩散时间对渗层质量的影响,研究了在纯O2气氛下Fe-Al合金表面的氧化情况.结果表明,8407钢经过冷喷涂铝后再进行低温扩散处理能够实现低温渗铝.渗铝后,在580℃以下,纯O2气氛条件下氧化,Fe-Al合金表面生成了FeO和Al2O3的混合氧化物.该氧化膜与铝液不润湿,可防止粘膜并改善模具的抗热疲劳和抗熔损性能.更多还原

【Abstract】 8407 steel is commonly used for Al alloy casting die. Aiming at improving anti-thermal-fatigue and anti-melting-loss properties of the die, the steel specimen with Al coating obtained by cold spraying of Al powder was diffused at 500 and 550℃, then oxidation treatment was carried out at 570℃ and pure O2 atmosphere to form a film Fe-Al-O spinel on the surface of specimen. The effects of temperature and time on the diffusion and those of temperature and atmosphere on the oxidation treatment were studied. The results show that the process that 8407 steel was treated by cold spraying of Al and followed by low-temperature diffusion treatment can realize low temperature aluminization. After diffusion treatment, a film of FeO-Al2O3 complex can be obtained on the specimen surface by oxidation treatment under 580℃ and pure O2 atmosphere. Such a film is not wettable with Al alloy melt and can thus prevent soldering and improve anti-thermal-fatigue and anti-melting-loss properties of the die.更多还原