Cause analysis of unqualified low-temperature impact performance of Q345qD bridge slab
The unsatisfactory low-temperature impact performance of Q345qD bridge slabs produced by one company was observed successively.The unqualified slabs were mainly concentrated in the thickness of 16 mm.Through a series of anal-ysis and testing on the unqualified samples submitted for inspection,the main reasons for the unqualified low-temperature impact performance of Q345qD steel plate were identified,i.e.,the severe segregation in the center of the sample as well as the presence of bainite structure in the segregation zone.At the same time,the nonmetallic inclusions in the sample also affected the low-temperature impact performance of the plate.The corresponding improvement measures were also proposed.
Q345qDlow temperature impact performancetissue segregationbainiteinclusion