由焊接热影响区的预期硬度分布优化焊接线能量的反问题研究

The heat affected zone softening and embrittlement phenomena in heat-resistant steel, stainless steel, pipeline steel and fine grain steels are important factors of degradation of the quality of welded joints. Therefore, it is necessary to apply a method to optimize source distribution by using expected hardness distribution in heat-affected zone.The project's main research include: firstly, constructing a direct heat conduction model dealing with latent heat in solid-liquid phase change,thermal radiation and solid transition, which select the Leblond model to simulate diffusion transformation, and choose the Koistinen model to simulate non-diffusion transformation. Secondly, building a functional representing the difference between the calculated value and the expected value of hardness distribution in heat affected zone, and constructing an adjoint problem and a variation problem for the direct model based on iterative regularization method and variational principles. Finally, minimizing the functional by using the iterative method and obtaining a optimal heat source.The project will establish the association of welding process and mechanical properties of heat affected zone, and could provide scientific guidance for the further optimization of welding process.

耐热钢、不锈钢和细晶粒钢中的焊接热影响区软化和脆化是焊接接头质量恶化的主要原因，对焊接结构安全运行造成了重大的影响。因此新型热影响区软化和脆化预防方法研究具有重要意义。本项目拟根据热影响区预期硬度分布来反演焊接热源分布。首先构建以热传导为基础，考虑固态组织相变和固液相变潜热以及热辐射现象的正向模型，其中选择Leblond模型模拟扩散型相变，选择Koistinen模型模拟非扩散型相变；然后构建反映热影响区硬度分布的预期值和计算值差值的泛函，依据正则迭代法和变分原理建立正向模型的辅助方程和变分方程；最后利用正则迭代法来寻求泛函的最小值，获得热输入的最优解。本项目将实现焊接工艺与热影响区力学性能的有机关联，为进一步优化焊接工艺提供科学依据

内容获取失败，请点击重试