If steam power appeared on warships before gunpowder, would ramming become dominant?
Short answer
Probably yes: without gunpowder weapons, powered hulls would make ramming and reinforced bows much more important.
Notes
Ramming would probably dominate naval combat if steam warships appeared before gunpowder. Ships could still carry archers, windlass-driven weapons, and possibly steam-powered crossbow-style or other tension weapons. Ramming could damage or sink both vessels, even in modern conditions. A purpose-built ram would therefore need a reinforced bow and forward structure to withstand impact.