铁-碳-硅合金的硅脆与硅的偏析

The Silicon Brittleness and Its Segregation in Fe C Si Alloys

硅在铁素体晶界上没有富集，硅在石墨球周围存在着明显的偏析。高温退火能消除石墨球周围的偏析。硅量低于硅脆的临界硅含量时，随着偏析的消除韧性有所增加；硅量高于硅脆的临界硅含量时，其脆性不因偏析消除而减少，反而有所增加。指出偏析不是引起硅脆的根本原因，硅脆是固溶体发生有序转变的结果。

Investigation was carried out into the silicon brittleness and its segregation in Fe C Si alloys,the results showed that there isn′t Si enrichment on the grain boundary of ferrite,but it has slight negative segregation,the silicon around the graphite nodules exhibits marked segregation,which can be eliminaled by annealing treatment for a prolonged period at high temperature.For a silicon level below Si brittleness point,the toughness of Fe C Si alloys increases with eliminating Si segregation;for a silicon level above Si brittleness point,the Si brittleness increases some with eliminating Si segregation.The segregation was found not to be a main cause of the Si brittleness,which may arises from ordered transformation of the solid solution.