在局域平衡的假设下,本文把普里高津的耗散结构理论用于金属的凝固理论,建立了一个非平衡态,开放体系的金属结晶凝固模型。用该模型建立了金属结晶凝固的稳定性转变的判别式,导出了金属凝固时的临界过冷度方程。用该方程求解的部分纯金属的过冷度同已知的金属凝固过冷度十分接近。 Under the assumption of local equilibrium, this paper applies the theory of dissipative structure of Prigogine to the solidification theory of metal, and establishes a non-equilibrium and open-system metal crystallization solidification model. With this model, the discriminant of the transition of the stability of the solidification of the metal crystal is established, and the critical undercooling equation of the metal is deduced. The partial supercooling of some of the pure metals solved by this equation is very close to the known metal undercooling.