Analysis on Combination of Strength and Impact Toughness from Stress-strain Curves of 06Ni9 Steel
Four group stress-strain curves with various characteristics were selected to analyze relationship between the curve characteristic and the combination of strength and impact toughness.The results show that,for a given 06Ni9 steel,an excellent combination of strength and impact toughness will obtain if there is an obvious yield phenomenon,i.e.,yield point and yield elongation in the stress-strain curve,which means that the specimen can meet the need of mechanical properties.At the same time,it points out that the yield strength of 06Ni9 steel is determined from carbon atom concentration segregated in the vicinity of edge dislocations in the ferrite after tempering,while the impact toughness depends on the quantities of retained austenite and the concentration of alloying elements dissolved in the retained austenite.