irst, create a class to hold your parameters:
public class PkRk {
    public int pk { get; set; }
    public int rk { get; set; }
}
then, use the Html.Action passing the parameters:
Html.Action("PkRkAction", new { pkrk = new PkRk { pk=400, rk=500} })
and use in Controller:
public ActionResult PkRkAction(PkRk pkrk) {
    return PartialView(pkrk);
}