P92钢的蠕变行为研究

来源期刊：钢铁2010年第9期

论文作者：赵强 彭先宽 丛相州 安威

文章页码：82 - 85

关键词：P92钢； 持久强度； Norton应力指数； 强化机制

Key words：P92 steel； creep rupture strength； Norton stress exponent； strengthening mechanism

摘    要：在不同温度和压力条件下完成P92钢的蠕变及持久试验,采用SEM、TEM研究P92钢的强化机制及退化机制。持久试验外推强度同欧洲蠕变委员会公布的数据基本相同。Norton应力指数数值表明,高应力阶段的蠕变机制为位错蠕变。组织观察结果表明:P92钢的主要强化机制为位错强化及弥散强化,淬火得到的马氏体内部有高密度的位错,板条间的碳化物M₂₃C₆及弥散分布碳氮化物MX是P92钢热强性高的原因。随着位错密度的降低及析出相的粗化,P92钢的高温耐热性也降低。

Abstract: The creep tests were finished on different temperatures and stresses.The strengthening and degradation mechanism were analyzed by SEM and TEM.The extrapolated creep rupture strengths were similar to the data declared by ECCC.The values of Norton stress exponents of high stresses creep indicate that the creep mechanism is dislocation mechanism.The results of microstructure investigation show that the strengthening mechanism of P92 steel is dislocation and dispersion strengthening.There are high density dislocations inside the martensite lath.Carbide M₂₃C₆ along the martensite lath and dispersed carbonitride MX are the reason why P92 steel have a high strength.The heat resistance of P92 steel decreases with the decreasing dislocation density and precipitated phases coarsening.