A B757-200 Captain reported his First Officer refused to pitch up beyond 20 degrees on takeoff even when the airspeed was increasing rapidly. The First Officer was replaced for the rest of the trip sequence.

Narrative

The First Officer was flying. During the takeoff; I noticed that the speed of the plane was increasing more than normal. At 300 FT AGL I called out V2+40! The First Officer did not respond or increase pitch. I said you need to pull up a little more; again no response. By that time we were above 800 feet AGL and back to normal increasing airspeed. Above 10;000 feet MSL I mentioned something about going to 25 degrees nose up on takeoff. He said that that was too much. Above 18;000 we talked about it. He told me that he does not go above 20 degrees nose up. I asked the First Officer that on the next legs that he flew to go up to 25 degrees nose up to hold V2+15 and he said 'no'! We had a Flight Manager on the flight so I asked him to come up after landing. The First Officer again said that he would not go above 20 degrees nose up to try to maintain V2+15. So the Flight Manager told me that we would look for a new First Officer to fly the rest of the trip. I mentioned that I could fly all the takeoffs and the First Officer do all the landings; but that was not OK with the First Officer.