Graf, 18, took just 45 minutes to defeat Kohde-Kilsch, despite dropping the first two games at love.
On Wednesday night, defending champion Stefan Edberg withstood a stern challenge from unseeded Soviet Andrei Chesnokov to advance to the semifinals with a 4-6, 7-6 (7-5), 6-4, 6-4 victory.
Graf's win put her in a Grand Slam final for the fourth time in her career. In the final Saturday, she will face Chris Evert or Martina Navratilova, who met in today's other semifinal.
Graf's victory extended her winning streak to 20 matches. Her last loss was to Navratilova in the U.S. Open final.
Graf extended her record against Kohde-Kilsch to 5-2.
Graf reeled off six games in a row in the first set, exploiting the lack of mobility and poor volleying of eighth-seeded Kohde-Kilsch, who was plagued by a pulled tendon in her right foot.
"I just tried to concentrate on my service, but I was trying too much in the beginning," Graf said.
Graf has not lost a set in her first six matches in the tournament.
In men's semifinals Friday, it will be top-seeded Ivan Lendl against Wimbledon champion Pat Cash of Australia, and Edberg and fellow Swede Mats Wilander.
The turning point of the Edberg's match came in the second-set tiebreaker at 5-5 when he appeared to hit a forehand out of court. The ball was ruled "out" by the linesman, but West German umpire Bruno Rubeuh overruled and called for the point to be replayed.
If the linesman's call had stood, Chesnokov would have had set point for a two sets to none lead. Instead, Edberg hit a forehand volley for 6-5 and followed with a service winner to end the tiebreaker and even the match.
Although disappointed about the incident, Chesnokov did not dispute the umpire's call.