从焊态到热处理态的新型含氮镍基熔敷金属显微组织演变特征及力学性能

Microstructure Evolution Characteristics and Mechanical Properties of a Novel Nitrogenous Nickel-Based Deposited Metal from Gas Metal Arc Welded State to Heat-Treated State

摘要:

采用气体保护金属极弧焊制备了新型含氮镍基熔敷金属，然后分别对其进行固溶处理、固溶和时效处理。研究了不同状态下的熔覆金属微观结构和拉伸性能的变化。结果表明，添加W和N元素后，沉积金属的高温抗拉伸强度表现良好。合金样品的晶粒尺寸较大，且在晶界处出现了花瓣状的Laves相。固溶处理后的样品晶粒尺寸减小，Laves相消失，但金属的屈服强度和伸长率都有所下降。固溶和时效处理后的样品晶粒尺寸更加均匀，晶体内析出了纳米级M(C, N)相，晶界处形成了M₂₃C₆相，样品的屈服强度和极限抗拉伸强度均高于其他样品，但塑性最低。主要变形机制是单位位错a/2<110>切削析出相。

Abstract:

A novel nitrogenous nickel-based deposited metal was prepared by gas metal arc welding. Subsequently, solid solution treatment as well as solution and aging treatments were conducted on the prepared metal to study the evolution of microstructure and tensile properties at different states. Results show that the high-temperature tensile strength of the deposited metal exhibits good performance after the addition of W and N. The grain size of the sample is large, and petal-like Laves phase appears at the grain boundaries. After solid solution treatment, the grain size decreases, and the Laves phase disappears. However, both the yield strength and elongation of the deposited metal decrease. The grain size of the samples after solid solution and aging treatment is more uniform, nanoscale M(C, N) phases are precipitated within the crystals, and M₂₃C₆ phase forms at grain boundaries. The yield strength and ultimate tensile strength of this sample are higher than those of the other samples, but its plasticity is the lowest. The main deformation mechanism is the unit dislocation a/2<110> cutting the precipitation phase.