Drag chain conveyor material

I don't quite understand the situation other than it sounds like there was grinding contact between two steel parts such that the conveyor no longer functions as intended. So there are two possibilities.....either the parts were designed for contact and the inappropriate steel was specified or the parts were not designed for contact and the steel was forced to resist a condition that it was not designed for. The solution would be to fix the condition causing contact if it was not designed for such or replace the steel with a more appropriate grade that can better resist contact. I suppose there is a third possibility that the thing functioned as designed and just wore out and needs to be replaced as part of routine maintenance.