Failure Analysis on Brittle Cracking of CB30 Casting Steel Connecting Rings

Cracking reasons of CB30 casting ferrite stainless steel connecting rings at the ingate positions were analyzed. The results show that the existence of martensite embrittlement phase in microstructure of the CB30 casting steel is the main reason for the brittle cracking of the casting parts. And this kind of brittle cracking of casting ferrite stainless steel ring type parts could be avoided effectively by improving the ingate structure, changing the de-shelling method and extending the annealing time.