Steel for automobile engine connecting rod as well as manufacturing method thereof

Abstract

The invention provides steel for an automobile engine connecting rod as well as a manufacturing method thereof. The steel for the connecting rod comprises the following components in percentage by weight: 0.32 to 0.40 percent of C, 0.40 to 0.70 percent of Si, 0.80 to 0.95 percent of Mn, 0.025 to 0.040 percent of S, 0.030 to 0.045 percent of P, 0.10 to 0.25 percent of Cr, less than 0.10 percent ofMo, 0.08 to 0.20 percent of Nb, 0.015 to 0.035 percent of Ti, less than or equal to 0.10 percent of Ni, 0.012 to 0.020 percent of N, less than or equal to 15*10<-6> of O and the balance of Fe and unavoidable impurities. The manufacturing method comprises the steps of performing converter smelting, performing external refining, performing continuous casting, performing casting blank slow cooling aswell as heating and rolling. The steel for the connecting rod as well as the manufacturing method thereof can guarantee that the tensile strength is more than 1000 MPa, the yield strength is more than 700 MPa and sulfide inclusion is controlled to be within level 3.0; and the steel for the connecting steel has the characteristics of high processing property, high breaking property and long life.

Description

technical field [0001] The invention belongs to the technical field of metallurgical manufacture, and relates to the design and manufacturing method of a steel for a connecting rod, in particular to the manufacture and production of a non-quenched and tempered steel for a connecting rod of an automobile engine. Background technique [0002] With the advancement of automobile manufacturing, the requirements for non-quenched and tempered steel materials for automobile crankshafts, connecting rods and other parts are also increasing, and materials are required to have good processing performance, high strength and high toughness. The non-quenched and tempered steel mainly relies on the addition of Nb, Ti, V and other trace elements combined with the subsequent forging and controlled cooling process to control the strength of the parts in an appropriate range. [0003] In the document titled "35MnVS Easy-cutting Non-quenched and Tempered Steel" in the 04 issue of "Automobile T...

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Problems solved by technology

[0006] To sum up, at present, the composition design of V refinement is mainly adopted. The tensile strength of the current non-quenched and tempered connecting rod steel is difficult to be stably controlled above 950MPa, and due to the addition of a large amount of sulfur, it will form a grade Higher sulfide inclusions can improve the processing performance to a certain extent, but the sulfide will become the source of cracks and reduce the service life of the connecting rod

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