Effect of post-weld heat treatment on the mechanical performance of 2.25Cr-1Mo-0.2 V welded joints assessed via Small Punch Testing

Journal article

The influence of a post-weld heat treatment (PWHT) on the microstructure and mechanical behaviour of a 2.25Cr1Mo0.25 V weld was investigated. The study focused on three distinct regions: the base metal, the heat-affected zone (HAZ), and the weld metal. Due to the limitations in conducting standard mechanical tests on all the weld regions, particularly the HAZ, Small Punch Tests (SPT) were performed across all regions, while standard mechanical tests were conducted only when sufficient material was available. Microstructural characterisation involved microstructure identification, hardness profiling, X-ray diffraction measurements, and fractographic examination. The results demonstrate that the SPT method effectively characterises the mechanical behaviour of all weld regions. Furthermore, PWHT significantly enhances microstructural homogeneity and improves the mechanical performance of both the HAZ and weld metal. The treatment leads to relaxation of residual stresses and microstructural refinement, thereby increasing the resistance of welded components to mechanical failure.

Authors: Llera, MM; Álvarez, G; Zafra, A; Rodríguez, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer
• Journal: Welding in the World
• Volume: 69
• Issue: 12
• Pages: 3809-3821
• Publication date: 2025-09-05
• Acceptance date: 2025-08-17
• DOI: 10.1007/s40194-025-02150-y
• EISSN: 1878-6669
• ISSN: 0043-2288
• Language: English
• Keywords: Heat-affected zone (HAZ); Small Punch Test (SPT); Welded joint; Post-welding heat treatment (PWHT)