ALLOYED CONSTRUCTION STEEL HAVING INCREASED STRENGTH AND METHOD FOR HEAT STRENGTHENING A HOT-ROLLED PRODUCT

摘要

The invention relates to ferrous metallurgy and specifically to producing alloyed construction steel for manufacturing petroleum pump sucker rods. The proposed steel has the following composition, by mass percent: carbon: 0.40-0.45; silicon: 0.15-0.30; manganese: 0.75-1.00; sulfur: no more than 0.025; phosphorus: no more than 0.025; copper: no more than 0.30; nickel: no more than 0.30; chromium: 0.80-1.10; molybdenum: 0.15-0.25; aluminum: 0.02-0.05; boron: 0.00010-0.00025; nitrogen: no more than 0.008; iron and impurities: the remainder; and also a mode for heat treating a hot-rolled product, which includes normalization at 880°C, cooling in air and tempering at a temperature of 580-600°C. The technical result of the invention consists in obtaining a hot-rolled metal product for the manufacture of pump rods, which exhibits the requisite performance characteristics: minimum yield fluidity of 720 MPa, and yield strength of 930-1000 MPa, while maintaining plasticity at a level seen in comparable products.