How do I protect painted metal from Middle Schoolers

Submitted to Community Café

I am in the process of renovating my middle school media center. I have purchased the Ikea Marius stools to use in the space. These stools were only available in black so I am painting them. My students will be rough with them, moving them around the space and stacking them when not in use so I need to protect the paint as much as possible.

So far I have lightly sanded the metal legs  and spray painted them with Rustoleum 2X Gloss spray paint. Is there a durable clear coat that I can use to protect the paint from chipping?    If anyone can help, please let me know.

Thanks so much for you input.