Laser additive manufacturing method for high-carbon and high-strength gradient steel member

Abstract

The invention discloses a laser additive manufacturing method for a high-carbon and high-strength gradient steel member. The laser additive manufacturing method comprises the following steps that (1) the surface of a high-carbon eutectoid steel base material is pretreated; (2) Ni-V binary pure metal mixed transition layer powder is preset on the surface of the pretreated base material; (3) precipitation strengthening type stainless steel is adopted for laser additive manufacturing; and (4) subsequent heat treatment is carried out. According to the laser additive manufacturing method, in order to solve the problem that the application field is limited due to the poor plastic deformation processing capacity of high-carbon steel, the manner that the high-carbon and high-strength gradient steel member is formed by forming a complex structure area through low-carbon high-strength steel is provided, and in order to prevent intergranular coarse chromium carbide in a transition area from being formed and cracking under the action of internal stress, a Ni-V transition layer material is designed by itself; and the Ni element stabilizes austenite to enhance the solid solution capacity of the carbon element, meanwhile, the V element is utilized to preferentially consume the C element, and under proper laser additive manufacturing process parameters, formation of thick chromium carbide and cracks in the transition area is avoided.

Description

technical field [0001] The invention relates to the technical field of high-strength carbon steel structural parts, in particular to a high-carbon-high-strength gradient steel component and a laser additive manufacturing method thereof. Background technique [0002] High carbon steel with carbon content near the eutectoid point is widely used in industrial production fields such as tools and molds because of its low price and high strength and hardness. However, high carbon content often leads to poor inherent plastic deformation ability and toughness, and it cannot be manufactured into complex shape components through large deformation cold working and other processes. [0003] For complex structural areas of high-carbon steel components, low-carbon high-strength steels with comparable mechanical properties to high-carbon steels and excellent formability are used instead of high-carbon steels to form high-carbon-high-strength steel components that can give full play to the ...

AI Technical Summary

Problems solved by technology

However, due to the dilution of the eutectoid steel matrix during the additive process, the carbon content in the transition zone will increase significantly

The deposited low-carbon high-strength steel is rich in alloying elements in order to meet the strength requirements. In the transition zone, alloying elements such as Cr and Nb are easily combined with carbon elements provided by the high-carbon steel matrix to form coarse carbides distributed in the grain boundaries, reducing the grain size. boundary strength

Under the combined effects of thermal stress and structural stress, defects such as cracks are easily formed at the carbide-rich grain boundaries in the transition zone, which endangers the overall performance of the component

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