45钢的直流电场催渗粉末铝铬共渗

Powder Aluminochromizing Assisted by Direct Electric Field for 45 Steel

对作为正、负极的45钢试样,在一合适的直流电场中采用含铝铁、铬铁、氯化铵和二氧化硅的粉末渗剂进行了铝铬共渗。检测了渗层的显微组织、厚度、抗高温氧化性能和耐腐蚀性能。研究结果表明:直流电场显著提高了渗速,使铝铬共渗温度从1 000℃以上降低到了750℃。在4 A直流电场中于750℃铝铬共渗3 h的45钢试样,渗层深度达到了约120μm,比常规的铝铬共渗层约深3倍。经直流电场铝铬共渗的45钢的抗高温氧化性能和在10%H2SO4溶液中的耐腐蚀性能均得到了显著改善。

45 steel specimens as anode and cathode were aluminochromized in a suitable direct electric field with a powder agent consisting of ferroaluminum,ferrochromium,ammonium chloride,and silicon dioxide.The microstructure,thickness,high temperature oxidation resistance and corrosion resistance of the case were examined.The results showed that the direct electric field could speed significantly aluminochromizing,and reduce aluminochromizing temperature from more than 1 000℃ to 750℃.The 45 steel specimens developed about 120μm thick case during the aluminochromizing at 750℃ for 3 h in a direct electric field with amperage of 4 A,which was nearly three times larger than that developed by conventional aluminochromizing procedure.The resistances to high temperature oxidation and to corrosion in a 10%H2SO4 solution of 45 steel aluminochromized in direct electric field were obviously improved.