微量元素C和Mg对一种镍基高温合金组织和力学性能的影响

通过对微量元素C,Mg含量的调整,来研究C,Mg元素对一种镍基合金组织及性能的影响,结果表明:C含量不足时,合金组织中碳化物数量少,在合金组织中分布不均匀,合金持久性能较低;而适量提高C含量,碳化物均匀分布,持久寿命明显提高.Mg元素含量低时,不影响合金的组织,合金的力学性能没有明显改变;而当Mg含量过高时,晶界碳化物粗大,合金冲击韧性aK值较低,拉伸塑性也降低;当加入最佳Mg含量时,碳化物得到充分细化,晶界碳化物呈粒状分布,合金的aK值和拉伸延伸率δ值显著提高.

Influences of C and Mg on Microstructures and Mechanical Properties of a Nickel Base Superalloy

The influences of C and Mg on microstructures and mechanical properties of a nickel base superalloy were studied.The results showed that when C content was low,the amounts of carbides in the alloy was little and distribution of carbides was not uniform,therefore the stressrupture life was reduced;With the increasing of C content,the distribution of carbides became more uniform,so the stress-rupture life was increased.No obvious effects were found on the microstructures and mechanical properties of the alloy when Mg content was low.The carbides in grain-boundary became bigger when Mg content was high,therefore,the impac value and tensile plasticity were reduced.The carbides were fined with granular in grain-boundary with appropriate content of Mg,impact value and tensile elongation were increased obviously.