1800MPa-level plating-free thermoforming steel with low high-temperature friction coefficient and preparation method of 1800MPa-level plating-free thermoforming steel

Abstract

The invention discloses 1800MPa-level plating-free thermoforming steel with a low high-temperature friction coefficient and a preparation method of the 1800MPa-level plating-free thermoforming steel.Main chemical components of the 1800MPa-level plating-free thermoforming steel comprise, by mass percent, 0.25%-0.35% of C, not larger than 0.5% of Si, 0.5%-1.5% of Mn, not larger than 0.020% of P, not larger than 0.010% of S, not larger than 0.50% of Cr, 0.01%-0.06% of Al, not larger than 0.04% of Ti, not larger than 0.5% of Nb+V+Mo, not larger than 0.003% of B and the balance Fe and inevitable impurities. Through optimization to components and processes, the surface state of the plating-free thermoforming steel raw material is improved, and a good thermoforming steel raw material is providedfor subsequent preparation of thermoforming parts.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and relates to a 1800MPa grade non-coated hot-formed steel with a low and high-temperature friction coefficient and a preparation method thereof. Background technique [0002] With the continuous development of hot forming technology, the amount of hot stamping steel is also increasing. At present, the hot-formed steel widely used in the market is divided into coated products and uncoated products according to the coating state. [0003] For coated plate products, there is no need for a protective atmosphere in the furnace during the thermoforming process, and the presence of the coating makes it have good high-temperature oxidation resistance during the thermoforming process, and there is no need for shot blasting and oiling treatment after thermoforming, so it has been favored by many OEMs. However, since Al-Si coated hot-forming steel is restricted by patents and its functions depend on im...

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Problems solved by technology

However, the addition of 0.41-0.50% C in this patent increases the hardness of the quenched martensite, but it is actually not conducive to the plasticity and toughness of the formed part; the addition of 1.6-2.0% Mn is easy to produce a banded structure, which is harmful to the formed part. The cold bending performance is unfavorable; and the addition of 0.21-0.35% Ni increases the alloy cost of the product; and there will be a decarburization layer in the raw material of the hot-rolled finished product, and the decarburization layer will be further aggravated after hot forming, which will affect the finished parts after shot blasting. Profile size and surface quality

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