Steel sheet for hot stamping, manufacturing method thereof, and hot stamped formed body

Abstract

The present invention relates to a steel sheet for hot stamping excellent in scale adhesion during hot stamping, a method for producing the same, and a hot stamped formed body thereof. The steel sheet for hot stamping has the following composition: at least C: 0.100% to 0.600%, Si: 0.50% to 3.00%, Mn: 1.20% to 4.00%, Ti: 0.005% to 0.100%, and B: 0.0005% to 0.0100%, P: 0.100% or less, S: 0.0001% to 0.0100%, Al: 0.005% to 1.000%, N: 0.0100% or less, the rest is composed of Fe and impurities; the surface roughness of the steel plate is Rz> 2.5μm, coated with 50mg / m on the surface 2 ~1500mg / m 2 oiled.

Description

technical field [0001] The present invention relates to a steel sheet for hot stamping excellent in scale adhesion during hot stamping, a method for producing the same, and a hot stamped formed body thereof. Background technique [0002] In order to cope with the trend of increasing combustion efficiency in recent years, the weight reduction of components such as door armrests and side members of automobiles has been studied. In terms of materials, from the viewpoint of ensuring strength and crash safety even with thinner walls, we are promoting high strength of the steel plate. Hereinafter, strength means both tensile strength and yield strength. However, since the formability of the material deteriorates as the strength increases, it is necessary to manufacture a steel plate that satisfies both formability and high strength in order to reduce the weight of the above-mentioned members. As a method of obtaining high formability with high strength, there is TRIP (TRansforma...

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Problems solved by technology

However, when considering the forming of a high-strength steel sheet of 780 MPa or more, there is a problem that even if the forming temperature is increased, the strength of the steel plate is still high and it is difficult to form, or there is a problem that the strength of the steel plate after forming by heating is reduced and obtained. When it is less than prescribed strength

However, since the zinc plating layer or the Al plating layer melts during heating and turns into a liquid phase, there is a problem that zinc or Al adheres to the inside of the heating furnace and the mold during conveyance or pressing of the steel sheet.

Adhered zinc or Al deposits cause indentation flaws in the hot stamped body, and there is a problem that it adheres to the formed body and deteriorates the appearance

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