Delphi处理SoapHeader问题

要完成一个需要验证的WebService服务，终端需要发送的SOAP包如下：
<soapenv: Header xmlns:wsa="http://www.w3.org/2005/08/addressing">
  <IP>10.109.225.172 </IP>
  <Security>
    <UserInfo>
      <Name>hu </Name>
      <Password>123 </Password>
    </UserInfo>
    <UserId>
      <Id>1100231 </Id>
      <Password>123 </Password>
    </UserId>
  </Security> 
</soapenv:Header>

目前自定义了继承TSOAPHeader类，如下：
type
  UserInfo = class(TSOAPHeader)
  private
    FName: WideString;
    FPassword: WideString;
  published
    property Name: WideString read FName write FName;
    property Password: WideString read FPassword write FPassword;
  end;

  UserId= class(TSOAPHeader)
  private
    FId: WideString;
    FPassword: WideString;
  published
    property Id: WideString read FId write FId;
    property Password: WideString read FPassword write FPassword;
  end;


initia