用连续球压痕法评价钢断裂韧度

Fracture Toughness Evaluation of Steel by Continuous Ball Indentation Test

作为一种无损力学性能测试方法,球压痕法可以用来评价在役设备材料性能。为了探究球压痕法获得断裂韧度的可行性,本文对五种材料进行连续球压痕试验和三点弯试验,并将两种试验方法所得的断裂韧度KJC进行比较。结果表明,球压痕试验和三点弯试验获得的断裂韧度偏差在10%以内,可以满足一般性的工程应用要求。同时,用三维表面测量仪观察了压痕试验后试样的三维形貌,探究了"堆积"和"沉陷"现象对试验的影响。观察到的堆积高度均在50微米以下,对试验的影响可以忽略。

As a non-destructive test method of mechanical property, ball indentation test can be adopted to evaluate the material property of in-site equipment. In order to explore the feasibility of obtaining fracture toughness through indentation test, continuous indentation test and three-point bending test were conducted on five different steels to compare the KJC obtained from different tests. Deviation of fracture toughness obtained from different tests is within 10%, which can meet the general requirement in engineering practice. Three- dimensional observation equipment was also adopted to evaluate the effect of ＂pile-up＂ and ＂sink-in＇. Height of ＂pile-up＂ observed is lower than 50μm, which is thought negligible to the tests.