The team announced the signings Tuesday. Harrison will make $1.5 million per season beginning in 2013-14. He is scheduled to make $750,000 this season.
The 29-year-old Harrison led Carolina's defencemen with nine goals and blocked 132 shots. He is beginning his fourth season with the club.
The 22-year-old Boychuk will make $625,000 at the NHL level or $105,000 if he is sent to the minor leagues. Carolina's No. 1 pick in 2008 split last season between the Hurricanes and their AHL affiliate in Charlotte and had two assists in 16 games with the NHL club last season.