Cooling method for preventing microcracks on wheel steel continuous casting slabs

Abstract

The invention relates to a continuous casting process, especially relates to a cooling method for preventing microcracks on wheel steel continuous casting slabs. The method of the invention improves the secondary cooling technique in the wheel steel slab continuous casting process, can effectively prevents generation and expansion of the microcracks on the wheel steel continuous casting slabs, such as star like crack, check crack, transverse crack, etc., on the surface or under the surface. The cooling method is a secondary cooling technique, concretely comprising: when the casting blank passing through the two cooling zones, controlling surface temperature of the casting blank in a range from 950 DEG C to 990 DEG C at the support and guide zone, and controlling surface temperature of the casting blank in a range from 950 DEG C to 100 DEG C at pulling and straighten zone. The method can makes surface and subsurface coagulating organization compact for the wheel steel continuous casting slabs, eliminates defects of star like crack, check crack and transverse crack on the surface or under surface of the casting blank, flawless rate of casting blank reaching 100%, and provides high grade casting blank for producing high quality wheel steel.

Description

technical field [0001] The invention relates to a continuous casting process, in particular to a cooling method for preventing microcracks of wheel steel continuous casting slabs. Background technique [0002] The manufacturing process of automobile wheels and the service conditions of the wheels are very strict on the technical requirements of the materials used. In addition to having good strength and toughness matching, they should also have good stretch flangeability and good cold formability , high fatigue strength and good welding performance, which require excellent surface quality and internal quality of hot-rolled steel plates for making wheels. High-strength grades of hot-rolled steel are used to manufacture car wheels. Since the higher the strength, the poorer the stamping formability of the steel plate, it is required that the surface of the hot-rolled steel plate for the manufacture of automobile wheels should not have any micro-crack defects. Micro-crack defe...

AI Technical Summary

Problems solved by technology

[0006] When the inventor used a straight arc casting machine or an arc casting machine in the past, the casting speed of the billet in the secondary cooling zone was generally controlled at 0.4-1.6m / min, and the amount of cooling water and cooling intensity for the billet were shown in Table 1-5. , the surface temperature of the slab leaving the rear foot roll section and the zero section of the mold is 995-1070°C, and the surface temperature of the slab in the fan-shaped section is 885-970°C. According to this process, the slab produced by this process has crack defects and the product is qualified. rate only reaches 70% to 80%

When a horizontal casting machine is used, there are fewer crack defects than straight arc casting machines or arc casting machines, but no cracks cannot be avoided.

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