CN105603166A - Heat treatment technology for W18Cr4V cutter steel - Google Patents

Abstract

The invention discloses a heat treatment technology for a W18Cr4V cutter steel. The heat treatment technology comprises the following steps: 1) forging: heating temperature is 1200-1250 DEG C, the initial forging temperature is 1050-1100 DEG C, the final forging temperature is 850-900 DEG C, air cooling is carried out after forging; 2) annealing: heating temperature is 900 DEG C, insulation is carried out for 2-4 hours, isothermal temperature is 720 DEG C, insulation is carried out for 4-6 hours, furnace cooling is carried out to the temperature of 500 DEG C at a speed of 5-10 DEG C/h, air cooling is carried out; and 3) quenching and tempering: the quenching heating temperature is 860-870 DEG C, oil quenching is carried out, and then tempering is carried out for 2-4 hours at the temperature of 720-760 DEG C. The heat treatment technology can improve structure stability of the W18Cr4V cutter steel, and has comprehensive performances of high hot hardness, high wear resistance, and high toughness.

Description

A kind of Technology for Heating Processing of W18Cr4V shear steel

Technical field

The invention belongs to Technology for Heating Processing field, specifically a kind of Technology for Heating Processing of W18Cr4V shear steel.

Background technology

High-speed steel tool often runs into the problem of strain cracking in heat treatment process, and the cutter that size is large, shape is more complicated and elongated cutter distortion are particularly outstanding, and the former is easy to crack, and the latter is yielding. There are various structural transformations in cutter, due to the specific volume difference of each tissue in steel, therefore Volume Changes occurs in the time of phase transformation in heating and cooling process. Especially high-speed steel, quench cooled obtains the martensitic structure of high alloy degree recklessly, martensitic specific volume is large, volumetric expansion after cutter is quenched, on the other hand, because cutter has complicated geometry, structural transformation that heating and cooling are is non-to be carried out simultaneously, the place of some wedge angles easily causes that stress is concentrated, causes cutter distortion cracking. Thermal stress is cutter is that to produce internal-external temperature difference caused in heating and cooling, and owing to variously in workpiece table having the temperature difference, causing expand with heat and contract with cold inconsistent, the thermal conductivity of high-speed steel is poor, the effect of more causus stress. Raw material carbide segregation causes strain cracking, due to carbide in production practices, inhomogeneities, is that instrument is concentrated place's cracking along carbide, the endoporus cracking of cutter, and majority is that above-mentioned reason causes; The larger stress of the inner existence of cutter before quenching; In processing procedure, easily cause strain cracking, hardening heat is too high, and steel strength is declined greatly, therefore in heating and cooling process, easily deforms and ftractures. All cutters have overheated, burn-off phenomenon, cutter distortion is just large, easily causes cracking; Cooling too fast, under the complexing action of thermal stress and structural stress, easily cause strain cracking; Although cutter does not ftracture in quenching process, also easy to crack in drawing process. There is important function so the Technology for Heating Processing of its shear steel for improving structure of steel stability, improves the combination properties such as wearability and toughness, in order to obtain the material of high-quality more, need to heat-treat technique to it and need to strictly control.

Summary of the invention

The object of the invention is for Shortcomings part in above-mentioned technology, the invention provides a kind of novel W18Cr4V shear steel Technology for Heating Processing, can improve W18Cr4V shear steel structure stability, improve the combination properties such as wearability and toughness.

The technical scheme that realizes the object of the invention is as follows:

A Technology for Heating Processing for W18Cr4V shear steel, is characterized in that, comprises following steps:

(1) forge: 1200～1250 DEG C of heating-up temperatures, 1050～1100 DEG C of initial forging temperatures, final forging temperature 850-900 DEG C, air cooling after forging;

(2) annealing: 900 DEG C of heating-up temperatures, insulation 2～4h, 720 DEG C of isothermal temperatures, are chilled to 500 DEG C with the speed stove of 5～10 DEG C/h, the air cooling of coming out of the stove after insulation 4～6h;

(3) quenching and tempering: 860～870 DEG C of quenching temperatures, oil quenching, then 720-760 DEG C of lonneal 2-4h tempering.

The Technology for Heating Processing of a kind of W18Cr4V shear steel of the present invention, can improve the structure stability of W18Cr4V shear steel, has the combination properties such as higher red hardness and wearability, toughness.

Detailed description of the invention

Below in conjunction with embodiment, the invention will be further described:

A Technology for Heating Processing for W18Cr4V shear steel, comprises following steps:

(1) forge: 1200～1250 DEG C of heating-up temperatures, 1050～1100 DEG C of initial forging temperatures, final forging temperature 850-900 DEG C, air cooling after forging;

(2) annealing: 900 DEG C of heating-up temperatures, insulation 2～4h, 720 DEG C of isothermal temperatures, are chilled to 500 DEG C with the speed stove of 5～10 DEG C/h, the air cooling of coming out of the stove after insulation 4～6h;

(3) quenching and tempering: 860～870 DEG C of quenching temperatures, oil quenching, then 720-760 DEG C of lonneal 2-4h tempering.

The Technology for Heating Processing of a kind of W18Cr4V shear steel of the present invention, can improve the structure stability of W18Cr4V shear steel, has the combination properties such as higher red hardness and wearability, toughness.

More than describe preferred embodiment of the present invention in detail. Should be appreciated that those of ordinary skill in the art just can design according to the present invention make many modifications and variations without creative work. All technical staff in the art, all should be in by the determined protection domain of claims under this invention's idea on the basis of existing technology by the available technical scheme of logical analysis, reasoning, or a limited experiment.

Claims (1)

1. a Technology for Heating Processing for W18Cr4V shear steel, is characterized in that, comprises following steps:

(1) forge: 1200～1250 DEG C of heating-up temperatures, 1050～1100 DEG C of initial forging temperatures, final forging temperature 850-900 DEG C, air cooling after forging;

(2) annealing: 900 DEG C of heating-up temperatures, insulation 2～4h, 720 DEG C of isothermal temperatures, are chilled to 500 DEG C with the speed stove of 5～10 DEG C/h, the air cooling of coming out of the stove after insulation 4～6h;

(3) quenching and tempering: 860～870 DEG C of quenching temperatures, oil quenching, then 720-760 DEG C of lonneal 2-4h tempering.