摘要
利用示波冲击试验,对高强度30CrNiMnMoB 钢的脆断机理进行了研究。根据示波冲击的载荷—挠度曲线可得出 P_f—T和 P_(gy)—T曲线,由此计算出材料的本征性能——微观解理断裂应力(σ_f~*)。由 Griffith 断裂公式σ_f~*=[4E(γ_s+γ_p)/π(1-v^2)x]^(1/2),讨论控制裂纹失稳扩展的微观组织因素。结果表明,试验钢的σ_f~*随强度升高而增大,控制高强度钢裂纹失稳扩展的微观因素是马氏体板条束。
The mechanism of brittle fracture of high strength 30CrNiMnMoB steel has been investigated by means of instrumented impact test. P_f—T and P_(gy)—T curves were deduced from load-deflection curves obtained at various test temperature to attain a constitutive property of the steel-microscopic cleavage fracture stress σ_f~*. The Griffith equation σ_f~*=[4E(γ_s+γ_p)/π(1-ν)x]^(1/2) was adopted to identify the controlling microstructural parameter for unstable propagation of crack.It is shown by the results that σ_f~* increases as strength of the steel is raised and martensite packet size plays a key role in unstable fracture propagation.
出处
《钢铁》
CAS
CSCD
北大核心
1997年第7期49-53,共5页
Iron and Steel
关键词
高强度钢
示波冲击
马氏体板条束
脆性断裂
high strength steel
instrumented impact
microscopic cleavage fracture stress
martensit packet size
