9%Cr钢厚壁管道局部焊后热处理温度场的数值模拟

基于热源追踪法开发了一个能够根据控温点温度自动调整热输入的有限元程序. 使用该程序模拟了9%Cr钢管道的局部焊后热处理温度场分布,并进行了试验验证. 结果表明,模拟结果与试验结果吻合良好. 热处理温度场沿管道轴向呈近似抛物线状分布,沿径向呈近似线性分布. 距焊缝中心两倍壁厚范围内,管道内外壁温差均约为17~18 ℃. 按照目前国内焊后热处理规程推荐的参数进行热处理,均温区宽度能够满足要求,可以保证整个接头的热处理效果. 根据温度场分布,还确定了与管道内壁焊缝中心温度相同的外壁等效点位置,以监测热处理过程中管道内壁温度的变化.

Numerical simulation of temperature field in 9% Cr steel thick-wall pipe in local PWHT

A FE program which could adjust heat input automatically according to the temperature at the controlling point was developed based on the heat input tracking method. The temperature distributions of 9% Cr steel pipe in local post weld heat treatment (PWHT) was simulated by using this program. The simulation results were in good agreement with the experimental results. The temperature field distributed as a parabola at the axial direction. There existed approximate linear relationship between metal temperature and radial distance. The temperature variations between the outer wall and the inner wall was about 17~18 ℃ within the distance of two times wall thickness to the weld center. The calculated soak band width according to the local PWHT parameters recommend by current domestic standard was wide enough to meet the requirements of heat treatment. Equivalence point on the outer wall which had the same temperature as the weld center in inner wall was obtained in order to monitor the temperature variation in inner wall during PWHT.