论文部分内容阅读
完成了在室温与 350℃高温下国产新材料 T42NG和 T225NG钛合金钢的拉伸与低周疲劳系列试验研究，获得了四个单调 R- O本构模型和四个 M- C寿命估算模型。以这些模型为基础，系统地研究了材料的循环强化与软化规律，研究了温度系数λσ、λΔσ和λ Nf对材料静强度、循环强度和低周疲劳规律的影响效应。根据温度对寿命的影响系数λ Nf与应变幅Δε /2呈线性规律这一重要发现，提出考虑了温度效应、用于高温低周疲劳寿命估算的λ- M- C模型，并提出了一种较现行方法更简便的高温疲劳试验方法。钛合金 T42NG钢的高温强度特性和低周疲劳特性优于 T225NG钢。
The series of tensile and low cycle fatigue tests of T42NG and T225NG titanium alloy made at room temperature and high temperature of 350 ℃ were completed. Four monotonic R-O constitutive models and four M-C life estimation models were obtained. Based on these models, the laws of cyclic strengthening and softening of materials are studied systematically. The effects of temperature coefficients λσ, λΔσ and λNf on the static strength, cycle strength and low cycle fatigue of materials are studied. According to the important finding that the influence coefficient of temperature on life span λ Nf is linear with the strain amplitude Δε / 2, a λ-M-C model considering the temperature effect for high-temperature and low-cycle fatigue life estimation is proposed and a More convenient than the current method of high temperature fatigue test method. Titanium alloy T42NG steel high temperature strength characteristics and low cycle fatigue characteristics better than T225NG steel.