Steel for automotive engine expansion breaking connecting rod

The invention belongs to the field of non-quenched and tempered steel, and relates to steel for an automotive engine expansion breaking connecting rod, in particular to phosphorus and sulfur contained high-strength steel suitable for the automotive engine expansion breaking connecting rod. The steel for the automotive engine expansion breaking connecting rod comprises the following chemical elements by mass percent: 0.40-0.50% of C, 0.60-0.80% of Si, 1.10-1.30% of Mn, 0.030-0.050% of P, 0.025-0.045% of S, 0.10-0.20% of Cr, 0.15-0.25% of V, 0.0150-0.0250% of N, and the balance being Fe and unavoidable impurities. The steel for the automotive engine expansion breaking connecting rod is characterized in that data of relevant mechanical property of the steel are as follows: Rel is greater than or equal to 800MPa, Rm is greater than or equal to 1100MPa, A is greater than or equal to 10%, and Z is greater than or equal to 20%. Through scientific design of an alloy system, the steel with high strength, appropriate brittleness and good machinability for the automotive engine expansion breaking connecting rod can be produced without making important adjustment to the existing production technique, and the technical effect is significant.