Ledeburite II
Ledeburite II is a transformation form of ledeburite where austenite has transformed into pearlite or secondary cementite. This phase affects the mechanical behavior of hard cast iron grades.
Physikalisch-chemischer Wirkmechanismus
Ledeburite II forms through the transformation of primary ledeburite, where the austenite component turns into pearlite or secondary cementite. This happens under specific temperature and time conditions in the cast iron grade.
Metallurgical Relevance & Welding Risks
Ledeburite II's tendency can lead to increased stress buildup because pearlite and secondary cementite are less elastic than austenite. That can cause cracks or fractures in the weld area if the weld isn't cooled properly.
Werkstattpraxis & Handlungsanweisungen
To minimize the risk of cracks and fractures, the weld must be cooled slowly and in a controlled way. Cooling time should be at least 10 seconds to ensure even cooling. Avoid fast cooling since it can cause stress buildup.