Data received from angularjs to MVC controller is null - angularjs

Question

Dears, I have two classes Master and detail named by Raterequest and Raterequestdetails. I have created a viewmodel contains both of them.
in Angularjs i have an object contains rate and a list contains orderdetails.
when i debug the controller the data received is null for both
here is the code
Rate request class
public class RateRequests
{
public int RateRequestsID { get; set; }
public DateTime RateRequestsDate { get; set; }
public string RateRequestName { get; set; }
public string RateRequestType { get; set; }
public string RateRequestMode { get; set; }
}
Rate request details class
public class RateRequestsLines
{
public int RateRequestsLinesID { get; set; }
public int RateRequestsID { get; set; }
[ForeignKey("RateRequestsID")]
public virtual RateRequests RateRequestsFK { get; set; }
public short FCLCNTRS { get; set; }
public short FCLCNTRSSIZE { get; set; }
public string FCLCNTRSTYPE { get; set; }
}
Rate request view model
public class RateRequestViewModel
{
public RateRequests rate { get; set; }
public IEnumerable<RateRequestsLines> ratelines { get; set; }
}
Angularjs
var linkers = angular.module("linkers", [])
.service("linkersSrv", function ($http) {
var urlBase = "/LinkersEgypt/";
this.save = function (url, ratee) {
return $http({
method: "POST",
url: urlBase + "/" + url,
data: ratee,
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})
};
})
.controller("linkersCon", function ($scope, linkersSrv) {
$scope.fcl = [];
$scope.addFCL = function () {
$scope.fcl.push({ FCLCNTRS: $scope.ncntrs, FCLCNTRSSIZE: $scope.csize, FCLCNTRSTYPE: $scope.ctype });
console.log($scope.fcl);
}
$scope.save = function () {
var ratee = {
rate: {
RateRequestsDate: $scope.rdate,
RateRequestName: $scope.rname,
RateRequestType: $scope.rtype,
RateRequestMode: $scope.smode
},
RateRequestsLines: $scope.fcl
};
console.log(ratee);
var promisepost = linkersSrv.save("RateRequest/AddAllRate", ratee);
promisepost.then(function () {
toastr.success("Successfully saved");
})
}
})
Rate controller
[HttpPost]
public JsonResult AddAllRate (RateRequestViewModel rate)
{
return new JsonResult();
}
Any help
Thanks in advance