Nickel equivalent
Nickel equivalent is a metric that quantifies the effect of austenitizing elements in steels. It helps in calculating the austenite content and for microstructure calculation.
Physicochemical Mechanism of Action
The nickel equivalent measures the effect of elements like nickel, cobalt, chromium and molybdenum on the austenitizing behavior of the steel. Each of these elements acts similarly to nickel, so it is converted into a nickel equivalent.
Metallurgical Relevance & Welding Risks
Too high a nickel equivalent can lead to fusion problems and strength reduction. With too low a nickel equivalent, the structure can become unevenly austenitic, which leads to stress concentrations and possible cracks.
Workshop Practice & Instructions
When welding high-alloy steels with a high nickel equivalent, careful temperature control is necessary to stabilize the structure. With lower nickel equivalents, the cooling rate should be controlled to ensure an even austenitic structure.