Method for increasing effective boron content in low-alloy high-strength wear-resistant steel

Abstract

A method for increasing the effective boron content in low-alloy high-strength wear-resistant steel comprises the steps that (1) converter smelting is conducted, specifically, dephosphorization operation is conducted, argon is blown to the bottom in the whole process, point blowing oxygen is smaller than or equal to 500 m <3> after pouring, over blowing is avoided, aluminum blocks and lime are added into a steel ladle for early-stage deoxidation and slagging treatment, TO is smaller than or equal to 80 ppm, and N is smaller than or equal to 30 ppm; (2) LF refining is conducted, specifically, an aluminum wire is fed into the steel ladle, the condition that the content of acid-soluble aluminum in molten steel is 0.03-0.05 wt% is ensured, ferrotitanium is added after white slag is manufactured and desulfurized, ferroboron is added 3 minutes later, and argon is blown to the bottom of the steel ladle; (3) RH vacuum treatment is conducted, specifically, the treatment time is longer than or equal to 35 min, and after refining is finished, N in the molten steel is smaller than or equal to 40 ppm; and (4) slab continuous casting is conducted, specifically, argon purging is adopted before tundish pouring is started, a double-layer covering agent is adopted after pouring is started, and pouring is protected. According to the method, by controlling the oxygen content and the nitrogen content in the molten steel, acid-insoluble boron is reduced, the effective boron content is further increased, and the effective boron content in the steel billet reaches 85% or above.

Description

technical field [0001] The invention belongs to the technical field of steelmaking and relates to a method for increasing the effective boron content in low-alloy high-strength wear-resistant steel. Background technique [0002] Low-alloy high-strength wear-resistant steel has high wear resistance, high strength, high toughness and good welding performance, and has been widely used in machinery and equipment in coal mines, transportation, agriculture, construction, food processing and other industries. [0003] The improvement of the core quality of the wear-resistant steel plate can significantly improve the wear performance and prolong the service life of the equipment, which in turn mainly depends on the hardenability in heat treatment production. In the chemical composition system, boron is an important element for improving hardenability, and only a small amount (generally 10-20ppm) can be added to significantly increase the core hardness of wear-resistant steel. The b...

AI Technical Summary

Problems solved by technology

In actual production, after adding ferroboron, the acid-soluble boron content of molten steel is low and the acid-insoluble boron content is high, resulting in poor hardenability and low hardness performance of the wear-resistant steel core.

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