Carbon Equivalent (CEq)
Compute a steel's carbon equivalent by the (simplified) IIW formula, CEq = C + Mn/6 + Cr/5 + Ni/15, weighting the alloying elements' effect relative to carbon on the hardening and cracking tendency. It is the key weldability index: a CEq below 0.40 indicates easily weldable steel; above 0.45–0.50 it requires preheating and care to avoid cold cracking. Enter the carbon, manganese, chromium and nickel contents (%).
Resultado
—
Carbono equivalente (CEq)
Como prever se um aço vai trincar ao ser soldado? Pelo carbono equivalente. A ideia é genial: cada elemento de liga contribui para o endurecimento (e o risco de trincas) de forma equivalente a uma certa quantidade de carbono. A fórmula do IIW pondera essas contribuições: CEq = C + Mn/6 + Cr/5 + Ni/15 (aqui simplificada; a completa inclui Mo, V, Cu). O resultado é um indicador único da soldabilidade: CEq < 0,40 → aço facilmente soldável, sem cuidados especiais; 0,40–0,45 → atenção; > 0,45–0,50 → exige pré-aquecimento, controle de hidrogênio e às vezes tratamento térmico pós-soldagem para evitar a temida trinca a frio (induzida por hidrogênio) na zona afetada pelo calor. É o primeiro número que um engenheiro de soldagem consulta. Informe os teores de C, Mn, Cr e Ni.
Related Tools
Welding Preheat Temperature
Estimate the preheat temperature for welding, Tp = 350·√(CE − 0.25), as a function of the steel's carbon equivalent (CE). Preheating reduces the cooling rate, giving hydrogen time to escape and preventing the formation of brittle martensite and cold cracks in the heat-affected zone. Steels with a high CE require more preheating. Enter the steel's carbon equivalent.
Tensile Strength from Brinell Hardness
Estimate a carbon steel's tensile strength (Rm) from the Brinell hardness, Rm ≈ 3.45·HB, in MPa. There is a remarkably robust empirical correlation between hardness and strength in steels, which lets you estimate strength from a hardness test — fast, cheap and almost non-destructive — instead of a tensile test. Useful in inspection and quality control. Enter the Brinell hardness (HB).
Equivalent Stiffness (Springs in Parallel)
Calculate the equivalent stiffness of two springs in parallel, k_eq = k₁ + k₂, by adding the individual stiffnesses. The result, in the same unit (N/m), is always larger than the largest stiffness — springs in parallel are stiffer, since they share the load under the same displacement and the forces add. This is the case of mounts, isolators and supports placed side by side carrying the same component. Reducing spring assemblies to an equivalent stiffness is the first step to compute a vibrating system's natural frequency. Enter the two stiffnesses.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.