Nippon Steel Corp. reached Monday a negotiated settlement with a group of five former workers who filed a damages suit against the major steelmaker, saying they were discriminated against in wages because they were communists, the plaintiffs said. The five joined Fuji Iron & Steel Co., one of predecessors to Nippon Steel, from 1956 to 1962. They later joined the Japanese Communist Party. Fuji merged with Yawata Iron & Steel Co. in 1970 to become Nippon Steel.