Cook lean ground beef, onion and salt in heavy skillet until browned. Add flour and stir through meat, then add water and cook until it thickens, stirring well. Add catsup, brown sugar, and chili powder, mix well. Simmer 15 minutes. Add the can of corned beef broken in pieces. Simmer another 1 5 minutes. Serve on hamburger buns. May also be frozen.