采用冲击试验仪器化试验方法和拉伸试验方法对汽轮机缸体用耐热钢不同状态(未经时效、经过593 ℃时效5 600 h)的动态断裂韧度及抗拉强度和塑性进行了研究,同时进行了SEM和物相分析。结果表明,在不同试验温度条件下,与未时效相比,经时效后材料的KId值和断口的侧膨胀值均有所降低;抗拉强度稍有增加,塑性略有降低。在时效试样的晶内与晶界处碳化物数量略有增加,主要是含铬的M23C6相有微量从基体中弥散析出;部分碳化物颗粒发生聚集和长大,试样中第二相平均粒径相对稍大。

The dynamic fracture toughness ,tensile strength and plasticity of stream-turbine cylinder body steel on the different condition ( no aging ,593 ℃ aging 5 600 h) were studied by impact test-instrumented test method and tensile test method . The result was obtained. At different testing temperatures ,compared with no aging and after aging,the dynamic fracture toughness and the side-swell value of fracture were both decreased,the tensile strength increased in some sort and the plasticity decreased a little. The result from SEM analysis and the method of phase analysis by physics and chemistry was obtained. A small amount of carbide was precipitated from intracrystalline and intergranular of aging sample.And this was mostly because micro phase of M23C6 containing Cr was precipitated dispersedly from matrix.Some carbide particles became gathered and growing after aging,and the mean particle size of second-phase of aging sample became enlarged in some sort.