High-strength high-tenacity non-quenched-and-tempered round steel and preparation method

Abstract

The invention discloses high-strength high-tenacity non-quenched-and-tempered round steel, and relates to the technical field of non-quenched-and-tempered steel. The high-strength high-tenacity non-quenched-and-tempered round steel is prepared from the following chemical components by mass percent: 0.27%-0.33% of C, 0.40%-0.70% of Si, 0.10%-0.30% of Cr, 1.30%-1.65% of Mn, 0.065%-0.100% of S, 0.005%-0.040% of Al, 0.06%-0.020% of V, 0.010%-0.040% of Ti, 0.0120%-0.0250% of N, the balance of Fe and unavoidable impurities, wherein manganese equivalent Mneq is 1.70%-2.10%. The high-strength high-tenacity non-quenched-and-tempered round steel is capable of increasing a free-cutting element S with low cost, forming dispersed distribution of a sulfide and a V (N, C) compound, through continuous uniform cooling rolling and temperature control cooling after rolling, a high-tenacity non-tempering steel bar with a good mechanical property is obtained, wherein rolled metal ballistic work reaches 190 J or more.

Description

technical field [0001] The invention relates to the technical field of non-quenched and tempered steel, in particular to a high-strength and high-toughness non-quenched and tempered round steel and a preparation method thereof. Background technique [0002] Non-quenched and tempered round steel is a medium-carbon low-alloy structural steel with comprehensive mechanical properties equivalent to those of quenched and tempered heat treatment in hot-rolled state or normalized state or air-cooled state after forging. Less, thereby reducing energy consumption and production costs, so non-quenched and tempered steel has been valued by various countries and has been rapidly developed and applied. Existing non-quenched and tempered steel mainly improves strength and toughness by adding a certain amount of alloying elements such as Cr, Ni or V. After searching, it is found that the Chinese patent with the authorized announcement number of CN104032214A discloses "a non-quenched and tem...

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Problems solved by technology

Existing non-quenched and tempered steel mainly improves strength and toughness by adding a certain amount of alloying elements such as Cr, Ni or V. After searching, it is found that the Chinese patent with the authorized announcement number of CN104032214A discloses "a non-quenched and tempered steel with extremely Production process", the Chinese patent of CN106119711A discloses "non-quenched and tempered steel bar and its manufacturing method". The water-through cooling method is not adopted, which affects the production efficiency, and the impact energy of the produced bars is below 120J

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