Intermediate Stage Bainite

Intermediate bainite forms during transformation between the pearlite and martensite stages. The structure is tough and harder than pearlite, but softer and more deformable than martensite. In welding, you get it mainly when cooling is neither too fast nor too slow – too fast gives martensite, too slow gives pearlite. A balanced structure with bainite makes the weld less crack-sensitive and well loadable. For practice, this means: choose cooling conditions so that you don't tip into martensite formation, then the structure is fine.