X90管线钢不同工艺制度下的相间析出行为

发布时间：2018-07-04 22:13

  本文选题：X90管线钢 + 热模拟　； 参考：《沈阳航空航天大学》2017年硕士论文

【摘要】：随着石油和天然气资源的日益枯竭,开采难度日益增加,对管线用钢的强度、韧性、抗腐蚀和抗开裂等性能都提出了更高的要求。析出强化是管线钢除细晶强化以外最重要的一种强化方式,是微合金钢的发展方向之一。本文采用低碳的X90管线钢作为研究对象,通过不同的热模拟和热处理工艺,系统的研究了道次间隔时间、变形温度、变形速率和保温温度、时间对X90管线钢组织性能和第二相析出的影响。主要的内容如下:(1)通过热模拟实验,研究不同的道次时间间隔和不同变形温度对X90管线钢组织和硬度的影响。结果表明:随着道次间隔时间的延长和变形温度的升高,其硬度变化趋势均为先升高后降低,主要原因在于析出相影响奥氏体的再结晶,细化奥氏体晶粒,从而得到细化的组织。当变形温度为800℃,道次间隔时间为30s时,硬度最高,能获得较理想的组织。(2)通过热模拟试验,研究不同应变速率和变形后不同保温时间对X90管线钢组织和硬度的影响。研究结果表明,实验钢的硬度随着应变速率的增加而增加,主要是因为板条贝氏体和M-A岛含量有所增加;变形后保温时间为2min时,硬度最高,这与第二相的析出数量和尺寸有很大关系。(3)通过热模拟实验,对实验钢分别进行一道次和两道次变形,并以不同温度保温,研究变形量和保温温度对X90管线钢组织和析出相的影响。结果表明,经历两次变形后钢的硬度均比经历一次变形的硬度高,其主要受到析出的第二相粒子和贝氏体含量的影响。(4)通过热处理实验,对实验钢进行奥氏体化后不同温度和不同时间的保温处理,研究其对管线钢第二相粒子析出和组织性能的影响。研究结果表明:当试验钢在650℃保温30min后的强塑积最大,为16675MPa%,性能最好。主要受到析出相、组织以及晶粒大小的影响。
[Abstract]:With the depletion of oil and natural gas resources and the increasing difficulty of exploitation, the strength, toughness, corrosion resistance and cracking resistance of pipeline steel are required. Precipitation strengthening is one of the most important strengthening methods for pipeline steels besides fine grain strengthening and is one of the developing directions of microalloyed steels. In this paper, the low carbon X90 pipeline steel is used as the research object. Through different thermal simulation and heat treatment processes, the passage interval time, deformation temperature, deformation rate and heat preservation temperature are systematically studied. Effect of time on Microstructure and second Phase precipitation of X 90 Pipeline Steel. The main contents are as follows: (1) the effects of different pass intervals and different deformation temperatures on the microstructure and hardness of X90 pipeline steel were studied by thermal simulation experiments. The results show that with the increase of pass interval time and deformation temperature, the hardness changes tend to increase first and then decrease. The main reason is that the precipitation phase affects the recrystallization of austenite and refines the austenite grain. Thus, the fine structure is obtained. When the deformation temperature is 800 鈩，

本文编号：2097659