1Vaccari J A. Free machining Steels[J]. American Machinist and Automated Manufacturing, 1986, (8): 115.
2Toshiyuki Murakami,Tetsuo Shiraga. Free Cutting Steel Containing BN Inclusions Without Lead Addition[J]. NKK Techn Rep,2002, (178) :21.
3Takashi Iwamoto, Toshiyuki Hoshino, Akihiro Marsuzaki, et al. A New Developed Unleaded Free Cutting Steel Which Has Both of High Fatigue Strengh and Excellent Machinability U sing Graphitization of Carbon in the Steel[J]. Material Japan, 2003, 42(2):163.
4Iwamoto Takashi,Murakami Toshiyuki. Bar and Wire Steels for Gear and Valve of Automobile(Eco-Friendly Free Cutting Steel Without Lead Addition) [J]. JFE Teehn Rep,2004,(4) : 64.