镍-铜高温合金主蒸汽滤网开裂失效分析

FAILURE ANALYSIS ON CRACKING OF A MAIN STEAM FILTER NET OF NICKEL-CORPER HIGH TEMPERATURE ALLOY

对某电厂镍基高温合金制造的主蒸汽滤网的开裂失效进行了分析.结果表明,造成主蒸汽滤网开裂的主要原因是晶界高温氧化,断口呈典型的沿晶开裂特征.主蒸汽滤网内孔涂层的成分与主蒸汽滤网基体接近,主要是多出了氧元素,其组织为N i(Cu)+N i(Cu)O双相组织.内孔涂层上局部有开裂,进一步促进了基材的氧化与开裂.

In this paper,the cracking of a main steam filter net made of nickel base higt temperature alloy is analyzed. The results show that the main reason for the cracking was high temperature intergranular oxidation,with the fracture morphology being a typical intergranular cracking character. The coating on the inner surface of holes has a similar composition with the base metal except that it contains certain amount of oxygen, with a dual - phase structure of Ni （ Cu ） ＋ Ni （ Cu ） O. The cracks presented on the inner coating prornoted the intergranular oxidation of the base metal.