σ-Tlnε_0/ε-d^(-1/2)三维冷脆断裂控制图和机制图的研究

THREE DIMENTIONAL σ-Tln(?)_0/(?)-d^(-1/2) COLD BRITTLENESS CONTROLLING DIAGRAM AND MECHANISM'S DIAGRAM

从理论和实验两方面研究了38CrA钢光滑试样屈服强度σ_(ys)、断裂应力σ_f与A参量(A=Tlnε_0/ε)、晶粒尺寸d(-1/2)之间的综合关系,建立了σ-A-d^(-1/2)三维冷脆断裂控制图和断裂机制图。它们不仅可用于冷脆断裂的分析、诊断、预测、控制和预防,还可用于低温构件的设计、选材和安全评估。

In this paper, the comprehensive relationships among the yield strengthσ_(ys), fracture strength σ_f, parameter A (A=T 1nε_0/ε) and grain size d^(-1/2), are studied intheory and experiment for tensile specimens made of steel 38CrA. Three dimentional σ-Tin ε_0/ε-d^(-1/2) cold brittle fracture controlling diagram and fracture mechanism's diagram are thereby established. They can be used not only in analysis, diagnosis, prediction, controll and prevention of cold brittle fracture, but also in the design and choice of materials and safety evaluation for parts used under low temperatures.