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热作模具最普遍的失效形式之一是热疲劳。根据约束类型的不同,热疲劳可分成热应力疲劳和热机械疲劳两大类。模具热疲劳主要是内约束型的热应力疲劳,在循环加热和冷却过程中,由于截面上存在温度梯度,心部材料对型腔表层的自由热胀冷缩有约束作用,使表层在加热时受压缩热应力,冷却时受拉伸热应力。若此交变热应力超过钢的屈服强度,就会引起往复滑移,逐渐导致疲劳破坏。 3Cr2W8V钢是我国制造热作模具的基本钢号之一,使用量大。随着生产的不断发展,如何提高3Cr2W8V钢模具的热疲劳寿命,越来越受到人们重视。本工作拟研究热处
One of the most common forms of failure of hot die is thermal fatigue. According to the different types of constraints, thermal fatigue can be divided into thermal stress fatigue and thermal mechanical fatigue two categories. Mold thermal fatigue is mainly the internal constraint thermal stress fatigue, in the cycle of heating and cooling process, due to the temperature gradient exists in the cross section, the core material of the cavity surface free thermal expansion and contraction constraints, so that when the surface is heated Compressed thermal stress, stretching by thermal stress. If the alternating thermal stress exceeds the yield strength of steel, it will cause reciprocating slippage, and gradually lead to fatigue damage. 3Cr2W8V steel is one of the basic steel made in China for hot work die, the use of large. With the continuous development of production, how to improve the thermal fatigue life of 3Cr2W8V steel mold is getting more and more attention. This work intends to study heat treatment