Causes of quenching distortion characteristics of oil-Quenched work pieces
(Beijing Huali Fine Chemical Co., Beijing 102200, China)
Abstract: As compared with high-pressure gas quenching and low-temperature salt-bath quenching, the quenching distortion of oil-quenched work pieces features in irregularity and greater distortion. The one-to-one correspondence between the work piece surface temperature and surface heat flux density, based upon the wrong understanding of the temperature-cooling rate curve of quenching oil, cannot explain the cause of such feature. Tests indicate conditional non-one-to-one correspondence between surface temperature and surface heat flux density, which is resulted from the gas flow rules inside of steam blanket and the characteristics of the intermediate stage of quenching. Such non-one-to-one correspondence can explain greater quenching distortion and irregular distortion data. Only quenched by immersing work pieces into an evaporating liquid then has this king of distortion characteristics.
Keywords: quenching oil; quenching distortion；fine quenching technique