Time.time rotation going faster and faster

this is a line just to spin a spacecraft round and round as it files forwards. The trouble is that it spins slowly at the start of game, and then it spins faster and faster and goes crazy fast. I just want it to spin at a constant rate:

transform.rotation = steerot * Quaternion.AngleAxis(Time.time*0.5, Vector3.forward);

Try using deltaTime instead of time, this way you should get a constant speed. With time the value is small at the beginning but it keeps going up obviously and that gets your ship rotating faster and faster.

transform.rotation = steerot * Quaternion.AngleAxis(Time.deltaTime * 0.5, Vector3.forward);