Charpy impact test

Metallurgy

Materials science

Intermetallic

Laves phase

Impact energy

Lath

Thermodynamics

Physics

Alloy

Microstructure

Fracture toughness

Composite material

Brittleness

Martensite

Nucleation

Fracture mechanics

Toughness

AIP conference proceedings

The effect of short-term aging (100 h) at 650°C on the temperature dependence of impact toughness and fracture behavior of advanced 10% Cr steel with low N and high B contents was studied. The steel in tempered condition exhibits the ductile-brittle transition temperature (DBTT) of ∼10°C and the Charpy V-notch impact energy of 240 J/cm2 at a temperature of 20°C. Aging for 100 h at 650°C leads to the increase in the DBTT to 35°C and decrease in the impact toughness at 20°C to 90 J/cm2. Effect of the fine (up to 100 nm) Laves phase particles precipitated at lath/grain boundaries on the impact toughness is analyzed. The Laves phase particles serve as additional nucleation sites for microcracks/voids facilitating unstable crack propagation. This is the main reason for decreasing the stable crack propagation energy and impact toughness of the steel.

Effect of short-term aging on the impact toughness of advanced 10% Cr steel