Once std chipboard is soaked it loses structral integrity. Replace it. DO NOT (IMHO) use dehumidifiers to dry it out. It does it too quickly and you will see more damage as a consequence.

How long does it take for chipboard to dry out?

Keep the room's temperature between 80 and 90 degrees Fahrenheit for 36 to 48 hours in order to speed evaporation of the moisture from the air. The high temperature will help to keep water particles from finding their way back into the particle board.

Does it matter if chipboard gets wet?

Re: Wet Chipboard Flooring - Does this need replacing

Chances are it'll be fine; unless it has soaked for a longish time. once it's had a chance to dry out then try prodding it with a screwdriver.. if the screwdriver sinks in it needs replacing.