Low-alloy high-strength C-Mn-Al Q & P steel and method of manufacturing the same

Abstract

The invention relates to a low-alloyed and high-strength Q and amp of a C-Mn-Al system; P steel; and a manufacturing method thereof, which belong to the technical field of metal materials. The method comprises the following processing steps of: (1) smelting and cast blocking: the mass percentages of the components are as follows: 0.16 percent to 0.25 percent of C, less than or equal to 0.40 percent of Si, 1.20 percent to 1.60 percent of Mn, 1.0 percent to 1.5 percent of Al, less than or equal to 0.02 percent of P, less than or equal to 0.008 percent of S and the balance of ferrite. (2) rolling: after the multi-pass hot-rolling of rough rolling and finish rolling, wherein, the deformation of roughing pass is 10 percent to 30 percent, the total deformation of the finish rolling is more than 60 percent, a hot rolled plate is subjected to multi-pass cold rolling, the deformation is 5 percent to 50 percent, and the plate is rolled to be a thin plate with the thickness being 0.6 to 2.0mm. (3) heat treating: firstly, austenitizing of 850 to 930 DEG C is carried out in a heating furnace, temperature is kept for 100 to 200 seconds and then rapid quenching is carried out to reach 230 to 250 DEG C, the temperature is kept for 20 to 40 seconds, after that the temperature is kept in 300 to 400 DEG C for 120 to 3600 seconds, at last fast cooling is carried out to room temperature (the speed of the cooling is not less than 10 DEG C / s). The Q and amp and the P steel have economic components, good quality of the surface, high strength and good shaping resistance. The strength and ductility product can reach over 37000MPa question mark percent.

Description

technical field [0001] The invention belongs to the technical field of metal materials, and in particular relates to a low-alloy high-strength C-Mn-Al series Q&P steel and a manufacturing method thereof. Background technique [0002] With the rapid development of the automobile industry and the improvement of human awareness of environmental protection, the requirements for improving fuel efficiency and enhancing automobile safety are increasing. In order to improve the safety of automobiles and reduce the weight of the vehicle body, the research of high-strength steel (HSS) has become one of the hot spots in the research of steel materials in recent years. A large number of high-strength steel plates are used in automotive structural parts. In order to reduce the manufacturing cost of medium and high-strength automotive structural steel, steel types with low price, high strength and excellent formability have been developed, such as DP (Dual-Phase Steel) steel, that is, dua...

AI Technical Summary

Problems solved by technology

For Speer's research results, although the strength is higher, the plasticity is lower than that of the present invention, and the total strength-plastic product is lower than that of the present invention, and the Si content in its composition is high, the hot rolling performance is reduced, and the steel plate is reduced during the galvanizing process. poor wetting performance, which reduces the surface quality of the steel plate and poor coating performance of the workpiece

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