Der Einfluss der Korngroesse, des legierungsgehaltes und einer Kaltverformung auf die Bruchzaehigkeit

The mechanical properties of four brasses, of a copper-nickel-alloy, of pure iron and of an austenitic steel are determined from tensile tests and from J-Integral tests. For recrystallized and cold deformed alloys, one detects a qualitative relation between the fracture toughness and the strain hardening exponent from plane strain tensile tests. The grain size dependence of the fracture toughness of the recrystallized alloys is closely related to the grain size dependence of the strain hardening exponent. Using a fracture toughness model proposed by Schwalbe and Backfisch, agreement between the measured and calculated fracture toughness values is found for the austenitic steel.