论文部分内容阅读
通过对已有高Co-Ni二次硬化钢实验结果的分析,提出了基于纳米级奥氏体层的相变诱导塑性(TRIP)效应和纳米级M_2C碳化物析出的强韧化机理,并根据Aer Met100钢大量已有的实验数据,建立了综合考虑奥氏体相变摩尔体积增量、奥氏体层稳定性、奥氏体层厚度、奥氏体平衡含量、M_2C尺寸、M_2C平衡含量、成本控制等多个因素的设计准则。通过控制时效工艺,将高Co-Ni二次硬化钢中的M_2C相尺寸控制在1~5 nm,奥氏体层厚度控制在10~20 nm。M_2C和奥氏体的平衡含量被分别控制在19.5%和3.8%。根据设计准则分析了新型高Co-Ni二次硬化钢M54的时效工艺制度,模拟设计结果与显微组织实验观察结果基本吻合。设计得到的新型高Co-Ni二次硬化钢具有较好的强度(2021 MPa)和韧性(115 MPa·m1/2)。
Based on the analysis of the experimental results of the existing high Co-Ni secondary hardened steels, the phase-change induced plasticity (TRIP) effect and the strengthening and toughening mechanism of nanoscale M_2C carbides are proposed based on the nanoscale austenite layer. Aer Met100 steel has established a large number of existing experimental data to establish a comprehensive consideration of the molar volume increment of austenite transformation, the stability of the austenite layer, the austenite layer thickness, austenite balance content, M_2C size, M_2C equilibrium content, Cost control and many other factors in the design criteria. By controlling the aging process, the size of M_2C phase in high Co-Ni secondary hardened steel is controlled to 1 ~ 5 nm and the thickness of austenite layer is controlled at 10 ~ 20 nm. The equilibrium contents of M_2C and austenite were controlled at 19.5% and 3.8%, respectively. According to the design criteria, the aging process of the new type of high Co-Ni secondary hardened steel M54 was analyzed. The results of the simulation were in good agreement with the experimental observations of the microstructure. The designed new high Co-Ni secondary hardened steel has good strength (2021 MPa) and toughness (115 MPa · m1 / 2).