摘要
为了配合20万kW供热机组汽轮机末级叶片的研制工作,本文就不同锻比、不同预先热处理制度、不同调质工艺对国内试生产的20CrllMolV(国外通常称X20CrMoV-121)钢延性断裂韧度的影响进行了探讨。研究表明,足够大的锻比、采用锻造淬火+高温回火代替普通退火作为预处理并选用低温淬火(960℃淬油)、高温回火(660℃×5h)处理,可以获得更高的J_(1c)值。分析表明,由于显著改善了这类马氏体不锈钢调质态钢中碳化物的大小与分布,是提高其强韧性的主要原因。
This paper deals with the influence of different deformation ratio and heat treatment on the fracture toughness of 20Cr11Mol V steel. The results showed that under sufficient large deformation ratio condition, using quench hardening and high temperature tempering after forging instead of annealing as conditioning treatment, and thereafter a lower temperature hardening (960℃, oil quenching) and high temperature tempering (660℃×5h) process can obtain higher J_(1c) value. It is analysed that the improvement of the size and distribution of carbides in this martensitic stainless steel is the main cause of increasing the strength and toughness.
