【摘要】 对核工业用钢 2 0MnHR热影响区和焊缝疲劳裂纹扩展速率 (da/dN)进行了试验研究。试验采用CT试样 ,热影响区和焊缝的有效试样分别为 14件。用七点递增多项式法求 (da/dN) i与 (ΔK) i,并分别将热影响区和焊缝同一组 14个试样的 (ΔK) i和(da/dN) i数据点合在一起进行回归分析。结果发现了疲劳裂纹扩展速率的斜率转折点 ,并分别给出了以Paris公式表达的平面应变区和平面应力区da/dN与ΔK关系式。试验分析说明采用以平面应变性质为基础的Paris裂纹扩展速率定律应用于实际焊接结构具有一定安全性。更多还原

【Abstract】 The fatigue crack propagation rate test has been carried out for the HAZ and weld of 20MnHR steel used in nuclear industry.Compact tension (CT) specimens were used in the test.The number of valid HAZ and weld specimens is respectively 14.In test,(d a /d N ) I and (Δ K ) I of each group specimens were computed with seven point incremental polynomial technique.All (d a /d N ) I and (Δ K ) I data of 14 HAZ specimens and 14 weld specimens were respectively together to carry on regression analysis.As a result,found the inflective point of crack propagation rate,and brought forward respectively relation of (d a /d N ) I and (Δ K ) I by means of the Paris crack propagation formulas based on plane strain behavior and plane stress behavior.The test results and analyses showed that the Paris formulas based on plane strain behavior can be applied to practical welded structures with considerable confidence.更多还原