I have an aluminum flat handlebar with a slight sweep on my touring bike. It has a shallow gouge/scratch about 1/2 way around the bar right at the union between the bar and the left side of the stem. The bar is 6061T6 heat treated aluminum and fairly thin compared to the no-name aluminum bar on my beater bike. The gouge/scratch appears to have come from someone rotating the bar in the clamp without sufficiently loosening the clamp first and is deep enough to easily feel when running the tip of my fingernail across it. I have about 500 miles on this bike with the bar in that condition and have hit potholes and other assorted road hazards and the damage has not changed and it doesn't look like there is a crack. I've also put a lot of pressure on the bar in several directions to see if there was any flex or change and there was not.
My question is, should the bar be replaced? It appears structurally sound now, but what are the chances of a gouge/scratch like this becoming a crack or causing catastrophic failure?