Experimental low-alloy steel rails for subway tracks

An experimental batch of R50 low-alloy Э78XCΦ steel rails is produced. Alloying with chromium (0.55%) yields an anomalous combination of strength, plasticity, and impact strength. The microstructure of the metal consists of colonies of fine-grain predominately sorbite-like pearlite. If the content of nonmetallic inclusions in the steel is sufficiently low, this extends the working life of the subway rails.