Migrating master databases between clusters by detaching/attaching them
SQLServer can't work without a master database at all as it stores essential configuration information in it (such as the table of databases in the system), so it wouldn't allow you to detach it. However, provided the SQLServers being the exact same version, you'll probably run into no problems if you stop the SQLServer services in both ends, copy the master database files from the one system to another (keep the old ones just in case), and start the services agan. It will be safer if neither server has any other databases in the system.