Method for producing annealing-free vanadium-containing heat-resistant steel hot-rolled wire rod

Abstract

The invention provides a method for producing an annealing-free vanadium-containing heat-resistant steel hot-rolled wire rod. According to the method, a converter double-slag low-phosphorus-content control method is adopted to reduce direct cold forming cracking caused by localized enrichment of phosphides; a technology of dynamic soft reduction in continuous casting and long-term high-temperaturediffusion in a cogging process is adopted for effectively reducing segregation of alloying elements in a casting slab; a high-temperature oxidizing coatings is used for effectively avoiding the problem of difficult removal of composite oxide scales; low-temperature laying, low roller speed and other means for controlled rolling and controlled cooling are beneficial to phase transformation of austenite at a high temperature section to pearlite; and an off-line thermal-insulation cover can effectively reduce driving force of transformation of retained austenite to a martensite supercooled structure. The tensile strength of the vanadium-containing heat-resistant steel hot-rolled wire rod is 520-560 MPa, the structure is a combination of ferrite and pearlite, and a heat-resistant steel component directly processed by an annealing-free process by downstream users has good moldability and can maintain good high-temperature long-lasting strength when serving in a high-temperature environment.

Description

technical field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for producing hot-rolled wire rods of annealing-free vanadium-containing heat-resistant steel. Background technique

[0002] Due to its good high-temperature oxidation resistance and high creep rupture strength, heat-resistant steel is widely used in petroleum cracking pipe components, steam turbine blades, and turbine bolts. Alloying elements such as Cr, Mo, V, Nb, and Ti can precipitate dispersed second phase particles in the matrix, and fine grain and solid solution strengthening can effectively improve various high-temperature properties of the material.

[0003] Due to the high content of hardenability elements and microalloying elements in heat-resistant steel, and because of the small size of the wire rod, the cooling rate after final rolling and spinning is fast, especially in the part where the central alloy element segregation is more serious, it...

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