**Analytical Model to Compare and Select Creep Constitutive Equation for Stress Relief Investigation during Heat Treatment in Ferritic Welded Structure**

#### **Mengjia Hu <sup>1</sup> , Kejian Li <sup>1</sup> , Shanlin Li <sup>1</sup> , Zhipeng Cai 1,2,3,\* and Jiluan Pan <sup>1</sup>**


Received: 9 April 2020; Accepted: 21 May 2020; Published: 23 May 2020

**Abstract:** The one-dimensional analytical model was promoted to help select the creep constitutive equation and predict heat treatment temperature in a ferritic welded structure, along with neglecting the impact of structural constraint and deformation compatibility. The analytical solutions were compared with simulation results, which were validated with experimental measurements in a ferritic welded rotor. The as-welded and post weld heat treatment (PWHT) residual stresses on the inner and outer cylindrical surfaces were measured with the hole-drilling method (HDM) for validation. Based on the one-dimensional analytical model, different effects of Norton and Norton-Bailey creep constitutive equation on stress relief during heat treatment in a ferritic welded rotor were investigated.

**Keywords:** residual stress; creep; stress relief; welded rotor
