【摘要】 大型水轮机叶片属于复杂曲面结构铸件,在热处理过程中由于冷却不均和相变极易发生翘曲变形,为此建立一套非接触式的温度场和位移连续动态测量系统。该测量系统采用红外热像仪测量温度场,采用非接触式测量方法测量铸件的变形。采用此系统对某工厂叶片生产中热处理冷却阶段的温度场和变形进行实时的测量,得到热处理冷却过程中叶片的表面温度变化和动态变形。在正火和回火冷却阶段叶片出水边的变形量并不简单地与温度和时间成正比关系,在正火阶段出水边变形有2个极值点,回火阶段有1个极值点。叶片变形主要发生在正火冷却阶段,受到温度变化和相变的共同影响,回火冷却阶段变形较小,主要受温度变化的影响。这种测量方法和得到的测量结果对叶片铸件的热处理过程冷却和变形规律研究以及铸件热处理工艺优化具有重要意义。更多还原

【Abstract】 The hydraulic turbine blade is a kind of large,complex and curved casting.It is susceptible to significant warping deformation in the heat treatment process because of no-uniform cooling and phase transformation,which is a serious problem for the dimension control of the blade.A non-contact temperature field and dynamic displacement measurement system is established with the infrared thermal imaging system used for temperature measurement and special devices for the deformation measurement.It is adopted to investigate the temperature distribution and deformation behavior of a blade at the cooling stages of normalizing and tempering in production.The results reveal the temperature evolutions and dynamic deformation of the blade in heat treatment.The deformations of the blade mainly occur at the cooling stage of normalizing owing to the effect of uneven cooling and phase transformation.While,it is small during tempering in which only uneven cooling effect exists.This research and the results are of great significance to the exploration and study of the deformation behavior of hydraulic turbine blades.And the established system is useful for temperature fields and deformation measurement for parts during heat treatment.更多还原