不同组配P91钢焊接接头断裂性能分析

作为马氏体耐热钢，P91钢具有很强的抗氧化和抗高温蒸汽腐蚀性能，在大功率火力发电设备中得到广泛应用，而其接头的断裂性能对该材料的推广及应用至关重要。采用数值分析及实验的方法，讨论裂纹位于焊接接头的不同位置时，组配发生变化的焊接接头的断裂驱动力和断裂抵抗力。结果表明，材料组配的不同会对焊接接头的断裂驱动力产生一定的影响。从断裂阻力的角度来看，低组配焊接接头的断裂抵抗力要高于高组配。实际工程结构应采用低组配接头形式，以提高焊接接头的抗断性能。

Analysis on the Fracture Property for the P91 Steel's Mis-matched Welded Joints

As a martensite heat-resistant steel, the P91 steel has strong resistance to oxidation and corrosion resistance to the steam at elevated temperature, so it is widely used in the large power thermal power generation set. However, the fracture property is crucial for the steel to extend its application. The fracture driving force and fracture resistance of the mis-matched welded joints of the P91 steel at different locations are calculated and analyzed by the numerical analysis and test. The results show that mis-matched welded joints have some influences on fracture driving force. From the standpoint of the fracture resistance, the fracture resistance of the under-matched welded joint is higher than that of over-matched welded joint. The under-matched welded joints should be used in actual engineering structure to improve the fracture resistance.