Bad spheroidised annealing structure - 1.7102
The reason for bad annealing structure, at constructional and tool steels, is almost always an annealing with wrong heat treatment parameters. Temperature and annealing time play the largest role. The initial structure before annealing can affect the result also. For example, bainitische structures can get spheroidised better than a perlitic structure condition.
Rod wire 16,00 mm round - spheroidised