It takes about 53 quadrillion megatons of force to blow the planet up. Most characters in the ring can do this fairly easily. Freeza could do this back when he was a small fry. The ring allows fighters and god well above this degree of explosive power to fight to the fullest without immediately shattering everything. The fact it holds up as well as it does is phenomenal. Even diamond, the hardest natural occurring substance known to man (boron nitrite is harder but is man made), can be smashed or chipped with a good hammer.
This stage is resisting the force of an entire stars being shattered and exploding. Something no substance we know of can handle. The odds of Superman breaking it are high, as most contestants on the Tournament could do the same if they were so inclined. Because this Katchin would need to be billions of times stronger than diamond to withstand the power being thrown around by the fighters and by Superman. And that's unlikely.
Or its a cartoon and there is no reasonable explanation (but that's boring and I ain't about that life). I still think Superman could break it though. Especially since he has heat vision and heat can make it easier to break down molecules.
So my only question is... which Superman? Because most of the weak Supermen can't dream of breaking it. But the few high end ones would probably damage it. To what degree I can't tell you. I wish I knew the exact strength of the fictional material.
Dramatic Gecko was right. The ring is able to withstand a battle royale between a dozen GoD's, who are each far above universal in terms of power. Sure it got messed up pretty bad, but you can literally count on one hand how many incantations of Superman there are, capable of throwing around that kind of power.
Even someone like Superboy Prime wouldn't be able to just destroy the ring outright. Sure, he could do it over time, but most versions of Superman would probably break their hands on it.
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"Why is everybody so ****ing stupid?"- Kim Jong Il, Team America.