冷却条件对球铁组织和性能的影响

The Effect of Cooling Condition on The Structure and Property of Nodular Cast Iron

通过控制模拟试件的冷却条件，研究了冷却速度对球墨铸铁中石墨的形态、基体组织和机械性能的影响。在本试验所采用的工艺条件下，获得模拟试件中完全凝固层厚度δ、凝固速率Ｒ和球墨直径ｄ以及抗拉强度σｂ与凝固时间ｔ有下列关系：δ＝１．２９２ｔ０．７０４ｃｍ；Ｒ＝０．９１ｔ－０．２９６ｃｍ／ｍｉｎ；ｄ＝１．９５７ｔ０．３０４×１０－２ｍｍ；σｂ＝４３７．２２＋１０．３９ｔ－０．２２ｔ２ＭＰａ。

This paper studied the effect of cooling rate on the morphology of graphite nodular, the matrix structure and the mechanical properties of nodular cast iron abtained by contoolling the cooling condition of the simulating test pipce. The relations of the solidified layer thickness δ , solidification rate R and the graphite nodular diameter d as well as the tensile strength δ b to the local solidification time t are abtained experimentally as following: δ=1.292 t 0.704 cm ,R=0.91 t -0.296 cm/min ,d=1.957 t 0.304 ×10 -2 mm ,σ b =437.22+10.39 t-0.22 t 2 MPa