A kind of preparation method of high-strength 550l automobile frame steel

Abstract

The invention discloses a preparation method of high-strength 550L automobile frame steel. The composition of the frame steel is C: 0.080-0.11wt%, Si: ≤0.20wt%, Mn: 0.55-0.65wt%, P: ≤0.018wt%. %, S: ≤0.004wt%, Ti: 0.045~0.060wt%, Al: 0.020~0.035wt%, N: 0.0030~0.0045wt%, steel TO≤0.0020wt%, converter smelting tapping control: [C]: 0.06‑0.08%, [P]: ≤0.015%, [S]: ≤0.008%, [O] ≤400PPm, fluorite, calcium carbide, and active lime are mixed according to the mass ratio of 1:1:3 in converter tapping, During the tapping process of the converter, it is added three times at intervals of 1 minute, 2 minutes, and 3 minutes, and the target value of addition is 600kg / furnace; oxygen is fixed before LF refining treatment; continuous casting molten steel is cast with argon protection, and the heating temperature of the slab is 1210~ 1230°C, using a hot rolling mill to roll hot-rolled coils with a thickness of 3.0mm to 10mm, and the final rolling temperature is 854‑858°C.

Description

technical field [0001] The invention relates to a preparation method of a high-strength 550L automobile frame steel, which produces an automobile frame steel with high strength, high toughness and excellent cold stamping performance, and belongs to the field of iron and steel metallurgy. Background technique [0002] High-strength automobile frame steel is mainly used in the frame manufacture of trucks. The frame is the load-bearing part of the truck, which is composed of longitudinal beams and beams. All components are formed by cold stamping or rolling, and assembled by riveting. Therefore, the chassis frame of the car is the most important safety component of the truck and trailer. The weight reduction of truck chassis and frame is the key direction of the development of the automobile industry. The use of high-strength automobile frame steel to reduce the thickness and usage of steel plates and reduce the weight of automobiles is the development direction. The process...

AI Technical Summary

Problems solved by technology

[0011] Aiming at the low strength of the 510L automobile frame steel currently used in the market, the thickness of the steel plate required for processing the frame, the self-heaviness of the automobile and other deficiencies, the present invention proposes a preparation method of a high-strength 550L automobile frame steel, which can eliminate the longitudinal defects of high-strength automobile frame steel. Disadvantages such as warping after cutting (steel strips) and difficulty in cold forming. While improving the strength of the steel, it also improves the cold stamping performance and use efficiency of the steel.

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