Gd对中子吸收用双相不锈钢组织和力学性能的影响

Effects of Gd on Microstructure and Mechanical Properties of Duplex Stainless Steels for Neutron Absorbing

摘要:

研究了不同Gd含量对00Cr23Ni8Mo1.4Mn1.4Si0.5合金显微组织和力学性能的影响。结果表明，Gd元素在合金中主要有3种赋存状态，即Gd₂O₃、M₁₂Gd和M₃Gd相（M=Fe， Cr， Ni）。随着Gd含量的增加，含Gd析出相与铁素体相含量增加，而奥氏体相含量降低。氧化钆和2种含Gd相的析出是合金在热变形过程中开裂的主要原因，部分聚集的氧化钆颗粒与晶界上难以变形的含Gd相降低了合金的热延展性。随着Gd添加量的增加，合金的抗拉伸强度和截面收缩率均降低。此外，与M₁₂Gd相比，M₃Gd更为硬脆，对合金的力学性能破坏性更强。

Abstract:

The effects of different Gd contents on microstructure and mechanical properties of 00Cr23Ni8Mo1.4Mn1.4Si0.5 alloy were researched. Results indicate that element Gd exists mainly in three forms in the alloy: Gd₂O₃, M₁₂Gd, and M₃Gd phases (M=Fe, Cr, Ni). With the increase in Gd content, the contents of Gd-containing precipitate and ferrite phase are increased, whereas the austenite phase content is decreased. The Gd oxide and precipitation of two Gd-containing phases are the main causes of cracking in the alloy during the hot deformation process. The partially aggregated Gd oxide particles and the difficult-to-deform Gd-containing precipitates on the grain boundary jointly decrease the hot ductility of the alloy. With the increase in amount of Gd addition, the tensile strength and section shrinkage ratio of the alloy are decreased. Furthermore, M₃Gd is harder and more brittle, compared with M₁₂Gd, resulting in a more detrimental impact on the mechanical properties of alloy.