铝合金压铸用模具钢表面的渗铝氧化处理

Aluminization and oxidation surface treatment of steel for aluminium alloy casting die

对8407模具钢试样进行热浸渗铝,在试样表面形成了Fe-Al合金渗层.对渗铝试样进行高温氧化实验,使渗层表面形成了Fe-Al-O的混合氧化物.考察了渗铝温度和渗铝时间对渗层质量的影响;着重研究了不同氧化气氛下Fe-Al合金表面的氧化情况,确定了最佳高温氧化工艺.结果表明,8407钢热浸镀铝后,在600℃以下、纯O2气氛条件下氧化,Fe-Al合金表面生成了Fe3O4和Al2O的混合物.这层氧化膜与铝液不润湿,能较好地保护试样.因此这种工艺可能是合适的铝合金压铸模表面处理工艺.

Hot dip aluminization was carried out to form an Fe - Al layer on the sample surface of steel for aluminium alloy casting die. And then high temperature oxidation was carried out to form a layer of Fe - Al - O complex oxide. The effects of temperature and time on the aluminization layer ; and the effects of atmosphere, temperature and time on the oxidation layer were investigated to obtain the optimum oxidation condition. The results show that, a thin film of Fe304 -A120 complex oxide was formed on the Fe -Al layer under the condition of pure oxygen and 600℃. Such a film is not wettable with liquid Al alloy and can thus protect the steel surface. Threrefore, this may be a suitable process for surface treatment of steel for aluminium alloy casting die.