CAUSE ANALYSIS OF FRACTURE OCCURRED ON SCREWED HANGING ROD OF PHB TYPE CONSTANT FORCE SUSPENSION BRACKET IN ONE POWER PLANT

In order to determine the cause leading to fracture occurred on screwed hanging rod of PHB type constant force suspension bracket in one power plant,macroscopic analysis,mechanical performance test,metallographic examination,and scanning electronic microscope test have been carried out for the fractured screwed hanging rod.Results show that the main cause resulting in fracture of the screwed hanging rod is the very low impact toughness of material,being extremely brittle material,and far lower than the allowed value specified in the standards,hence,the fracture occurred under action of alternating tensile load and bending load.Besides,the PHB type suspension bracket has structure defects in design,it is recommended to amend and perfect the standard JB/T8130.1-1999.