回火处理对05Cr17Ni4Cu4Nb钢性能及晶间腐蚀敏感性的影响

Effect of tempering treatment on properties and intergranular corrosion sensitivity of 05Cr17Ni4Cu4Nb steel

利用金相显微镜、扫描电镜、透射电镜、硬度及冲击试验等手段,观察和测试05Cr17Ni4Cu4Nb马氏体不锈钢的组织和性能,通过晶间腐蚀试验研究了回火处理对其晶间腐蚀敏感性的影响。结果表明,经650℃×2 h回火处理后,固溶时效态05Cr17Ni4Cu4Nb沉淀硬化不锈钢中含Cu弥散强化相密度降低,尺寸增大,逆变奥氏体相沿原奥氏体相及原马氏体板条界处生成并长大,含Cr碳化物分解,Cr元素偏聚析出形成了条状析出相,但分布更为均匀,导致钢的强度降低,韧性提高,并且由于弥补了原贫Cr区的Cr元素,材料的晶间腐蚀敏感性降低。

The microstructure and properties of 05Crl7Ni4Cu4Nb martensitic stainless steel were observed and tested by means of metallography microscope,scanning electron microscope,transmission electron microscope,hardness and impact tests,respectively.The effect of tempering on its intergranular corrosion sensitivity was studied by intergranular corrosion test.The results show that after tempering at 650℃ for 2 h,the density and size of the Cu dispersion-strengthened phase in the tempered tested steel decrease and increase,respectively.The inverting austenite phase forms and grows along the boundary of the original austenite phase and the original martensitic lath,the Cr-containing carbides decompose,and the Cr element is separated out to form a strip precipitated phase,but the distribution of Cr element is more uniform,resulting in a decrease in the strength of the steel,an increase in toughness,and the intergranular corrosion sensitivity of the material is reduced due to the supplementation of Cr element in the original Cr poor region.