摘要
研究了试样壁厚对DD499单晶高温合金持久性能及其断裂特性的影响。在760℃/790MPa和1040℃/165MPa条件下,壁厚为0.8 mm和1.2 mm试样的持久寿命明显低于标准试样,表现出显著的薄壁效应,壁厚和持久塑性间没有明显的函数关系。在760℃/790 MPa条件下,0.8 mm厚度的试样主要以滑移开裂为主,随着壁厚的增加,解理断裂转向混合断裂,延性断裂因素增加。1 040℃/165 MPa条件,断裂特性相似,但壁厚为0.8 mm和1.2 mm试样断口表面存在着较厚的氧化层,其有效截面显著减少。
Influence of thin wall on stress rupture properties and the fracture character of DD499 single crystal superalloy were investigated. Under the condition of 760 ℃/790 MPa and 1040 ℃/165 MPa, stress rupture life of the samples with 0.8 mm or 1.2 mm thickness is significantly less than that of the standard sample, which exhibits thin wall effect. There is an ambiguous function relationship between thickness and stress rupture ductility. At 760 ℃ and 790 MPa, slip crack is the main fracture character of the specimen with 0.8 ram. The cleavage fracture turn to mixture fracture with the increase of wall thickness, the tensility fracture factor is increasing. At 1 040 ℃ and 165 MPa, the fracture surface with 0.8 mm or 1.2 mm thickness possesses relative thick oxidation layer though all test specimens represent similar cavity accumulation failure character, it induces that effective section evidently decreases.
出处
《铸造》
CAS
CSCD
北大核心
2014年第5期479-483,共5页
Foundry
基金
国家基础研究项目(2010CB631200
2010CB631206)
国家自然科学基金(50931004
51001103)
关键词
单晶合金
持久性能
薄壁效应
single crystal superalloy
stress rupture properties
thin wall effect
