Li Xiangqing

Bio: Li Xiangqing is an academic researcher from Zhejiang University of Technology. The author has contributed to research in topics: Materials science & Fracture toughness. The author has an hindex of 4, co-authored 17 publications receiving 56 citations. Previous affiliations of Li Xiangqing include Westlake University & Chinese Ministry of Education.

Nanoindentation creep behavior of RPV’s weld joint at room temperature

Abstract: SA508 Gr.3 steel has been widely used in nuclear reactor pressure vessels (RPV). Nuclear components are generally combined through arc welding processes, which always produces heterogeneous mechanical properties in heat affected zone (HAZ) of weld joint. In order to study mechanical heterogeneity of weld joint, HAZ was been divided into five small regions (HAZ1 to HAZ5) based on the distance from the weld center line. The elastic modulus, hardness, and creep deformations of five regions in HAZ were measured through nanoindentation, as well as base and weld metals. According to the experimental results, the HAZ2 region (belonging to the fine-grained HAZ) exhibited a significantly lower hardness and creep behavior. Strain rate sensitivities (SRS) in different regions were then estimated from the steady-state creep, and the HAZ2 region showed a relatively higher value. The influence of grain boundary fraction on the creep behavior of weld joints was discussed later. Furthermore, the results of SRS also indicated that the creep mechanism of tested regions could be dominated by dislocation activities.

Platform for testing structural integrity of reactor pressure vessel under IVR condition

Abstract: The invention discloses a platform for testing the structural integrity of a reactor pressure vessel under an IVR condition. The platform comprises a working condition simulation system, a data acquisition and analysis system, and a safety system. The working condition simulation system is provided with a water supply unit, a steam condensing unit, and a heating unit; the data acquisition system is composed of measuring elements of each unit; and the safety system is arranged on the periphery of the working condition simulation system. The boiling heat transfer process in a reactor pressure vessel can be simulated by controlling the water flow of a cooling unit and the heating power of a hot pool simulation unit; by measuring and simulating the wall temperature, strain, and pressure, the heat transfer characteristics of a reactor pressure vessel can be simulated and analyzed; a referential model is provided for the boiling heat transfer tests on a reactor pressure vessel; and the test platform has a simple and compact structure, can carry out structural integrity analysis on a simulated reactor pressure vessel, comprises a nitrogen gas pressurizing unit, thus can also carry out analysis on the heat transfer characteristics of a pressurized reactor pressure vessel, and has a wide application range.

The effects of tensile and compressive dwells on creep-fatigue behavior and fracture mechanism in welded joint of P92 steel

Abstract: The creep-fatigue interactions on the long-term service damage of P92 welded joint were investigated on the tensile and compressive holdings with a series of applied strains, respectively The local mechanical properties including hardness, elastic modulus and creep resistance of welded joint were uncovered using nanoindentation The features of fracture morphology and internal defects after CF tests were studied by scanning electron microscope Based on the characteristic of microstructural evolution and the variation in local mechanical properties, holding type effects of creep-fatigue interaction on the local creep behavior and fracture mechanism of the welds were systematically investigated