A heat treatment method for high-strength wear-resistant steel plate

Abstract

The invention relates to a heat treatment method for high-strength wear-resistant steel plates, which comprises the following steps in turn: I, controlling an original plate shape, wherein a hot-rolled steel plate is subjected to a hot rolling process and is subjected to 5-7-pass straightening by a straightener, so that the plate shape waviness of the steel plate is 2-4mm / 2m; II, performing surface treatment, namely performing shot blasting on the upper and lower surfaces of the steel plate by using a shot blasting machine; II, quenching, namely heating the steel plate in a roller hearth normalizing furnace together with the furnace to a critical point Ac3, namely 10-50DEG C, keeping the temperature at a rate of 1.5-2.0min / mm according to the thickness of the steel plate, discharging the steel plate at a rate of 0.10-0.50m / s into a quenching machine, and quenching to room temperature; and IV, tempering, namely performing low temperature tempering treatment on the roller hearth normalizing furnace at the temperature of between 350 and 380DEG C, and controlling the temperature keeping time at a rate of 3min / mm according to the thickness. In the heat treatment method for the high-strength wear-resistant steel plates, the roller hearth normalizing furnace and a common quenching machine are adopted, and the waviness of finished products is 3-6mm / 2m.

Description

technical field [0001] The invention relates to a heat treatment method for a high-strength wear-resistant steel plate, in particular to a heat treatment method for a low-alloy high-strength wear-resistant steel plate NM360. technical background [0002] High-strength wear-resistant steel plate belongs to low-alloy high-strength steel, which has the characteristics of high strength (or high hardness), high wear resistance, good plasticity and toughness, and weldability. Under different wear conditions, the wear resistance of the material is mainly determined by the hardness, and the wear resistance increases with the increase of the surface hardness of the material. NM360 refers to high-strength wear-resistant steel with a surface Brinell hardness HB of 360. The yield strength of the product is Rp0.2≥1000MPa, the tensile strength Rm≥1150MPa, and the elongation A≥10%. The matrix is ​​strengthened mainly through "quenching + low temperature It is realized by martensitic struc...

AI Technical Summary

Problems solved by technology

The establishment of the quenching mathematical model has many technical problems such as ①complex modeling and poor adaptability; ②difficulty in measuring related parameters; ③difficult to accurately determine the boundary conditions of the model; ④difficult to solve the model, and many other technical problems, and the development of the automatic control system for the heat treatment process is very difficult.

Therefore, for many traditional medium and heavy plate factories in China, the quenching machine control system often lacks a mathematical control model for high-strength carbon steel plate quenching and high flatness. The large stress difference leads to the unevenness of the steel plate after quenching is generally 13-25mm / m, which is far from the unevenness required by the user ≤ 6mm / m