中文摘要：

将有、无δ铁素体的P92钢管样在700和750℃分别时效1000，3000和5000h，采用电子探针-X射线能谱分析（EPMA-EDS）和复相分离技术（MPST）研究了δ铁索体对时效析出M23Ca及Laves相体积分数及相成分的影响．结果表明，在时效过程中，6铁素体的存在促进了M23Ca及Laves沿δ铁素体的界面析出，发生聚集与粗化，并为该过程提供Cr，Mo和W；在δ占铁素体的P92钢管样中，不同温度下，M23Ca体积分数随时效时间的变化速率不同；在有6铁素体的P92钢管样中，温度降低促进了Laves体积分数的增加，升高温度则有利于M23C6体积分数的增加．此外，提高时效温度和延长时效时间可促进2种析出相的粗化．

英文摘要：

Using the as-received P92 steel pipe steel samples with/without δ-ferrite as objects and EPMA-EDS＋MPST （multiphase separation technique）, this work investigated the effects of δ- ferrite on the volume fraction and composition of M23Cs and Laves phases precipitated in the ageing treatment at 700 and 750 ℃ for 1000, 3000 and 5000 h, respectively. The results are as follows. The existence of δ-ferrite promoted aggregation and coarsening of M23Cs and Laves particles precipitated along boundaries with its neighboring lath martensite at the expense of consuming Cr, Mo and W in δ-ferrite during the ageing treatments. Varying rate of the volume fraction of M23C6 with the ageing time for the samples without δ-ferrite would chang at different ageing temperatures, and also the volume fraction of Laves phase would increase with decreasing ageing temperature for the samples with δ-ferrite. Owing to a few amount of Laves formed at higher temperature, the volume fraction of M23Cs increased in the samples with δ-ferrite. And increasing ageing temperature and time stimulated the coarsening of particles precipitated in the pipe samples investigated. It is expected that the related information from this study on the effects of existence of δ-ferrite on the microstructural stability and high temperature properties of P92 can be used as a reference when needed.