Studies of the effect of thickness on the fracture toughness of grade 300 maraging steel, part 2.

Abstract

The fracture toughness of samples of grade 300 maraging steel sheet of varying thickness was determined in tensile test specimens containing a spark machined slot. A maximum fracture toughness of 105 MPa m2 was obtained in specimens in the thickness range 0.75 to 1.25 mm. The fracture surfaces of specimens over 0.5 mm thick contained both plane stress and plane strain areas, but below 0.5 mm fracture was entirely under plane stress conditions.