The influence of silicon on the impact and tensile properties of steels

The influence of Si on the impact and tensile behavior of steels has been examined. Analy-sis of the data in the literature shows that there is reasonable agreement on the affect of Si on tensile strength. However, the influence of Si on impact behavior seems to depend on an interrelationship with Mn and N, and also, on whether the steels are normalized or hot rolled. An explanation of this has been given in terms of varying degrees of grain-bound-ary segregation of N, dependent on the Si, Mn and matrix free N contents, and the effect of these variations onK _y value, and through this on impact properties. Atom probe, strain-aging and internal friction data are presented which give some support to this ar-gument. However, direct evidence to support a grain-boundary segregation theory is still awaited and further atom probe work is required.