DeLong Constitution Diagram
The DeLong constitution diagram extends the Schaeffler diagram by incorporating the influence of nitrogen on ferrite formation in austenitic chromium-nickel welding rods. It helps refine delta ferrite content to avoid hot cracking.
Physicochemical Mechanism of Action
The DeLong constitution diagram shows ferrite formation in austenitic chromium-nickel welding rods under the influence of temperature and time. It takes into account the addition of nitrogen, which affects ferrite formation.
Metallurgical Relevance & Welding Risks
Too high a delta ferrite content can cause hot cracking because ferrite is softer and less tough than austenite. The DeLong diagram helps set optimal cooling temperature and time to avoid these risks.
Workshop Practice & Instructions
Use the DeLong constitution diagram to control ferrite formation in chromium-nickel welding rods. Set cooling temperature and time so that delta ferrite content stays below 5%. This prevents hot cracking and increases weld toughness.