Liquid die-forging and rolling composite forming method for die steel special-section large ring piece

Abstract

The invention discloses a liquid die-forging and rolling composite forming method for a die steel special-section large ring piece. The method comprises the following steps of: smelting, performing liquid die-forging, homogenizing, performing afterheat isothermal rolling, performing thermal treatment and performing fine adjustment, wherein the step of performing liquid die-forging comprises the following substeps of: fixing a liquid die-forging die on an indirect extrusion casting machine, and quantitatively pouring a die steel solution obtained through smelting into the liquid die-forging die at the pouring temperature of between 1,600 and 1,650 DEG C under the pressurization speed of between 30 and 60 mm / s, wherein the filling time is 1 to 6 seconds, and the specific pressure is 150 to 200 MPa; and keeping the pressure of between 150 and 200 MPa for 35 to 100 seconds, and thus obtaining a similar final section ring blank; and the step of performing afterheat isothermal rolling comprises the following substeps of: cooling the homogenized similar final section ring blank to the temperature of between 1,000 and 1,180 DEG C, and performing afterheat isothermal rolling on a radial shaft composite ring rolling machine. By the liquid die-forging and rolling composite forming method for the die steel special-section large ring piece, the process flow of manufacturing a blank of an alloy ring piece can be simplified, the cost can be reduced, and the production efficiency can be improved; and furthermore, the microstructure state of the die steel ring piece can be effectively improved, and the comprehensive mechanical property can be improved.

Description

technical field [0001] The invention relates to a short-process processing and forming method for large-diameter metal rings with complex cross-sections, in particular to a liquid die forging and rolling composite forming method for large-scale rings with different cross-sections of die steel. Background technique [0002] Large rings made of die steel are mainly used in fields such as oil and gas, and the working environment is harsh. The special use environment puts forward almost strict requirements on the dimensional accuracy and comprehensive mechanical properties of the ring parts: on the one hand, the parts are required to have high-precision external dimensions to avoid subsequent machining, which wastes a lot of manpower and material resources and seriously reduces the performance of the ring parts. ; On the other hand, the parts are required to have an excellent organizational state in order to meet the requirements of comprehensive mechanical properties. [0003]...

AI Technical Summary

Problems solved by technology

[0004]1) The process is lengthy, with many procedures and low production efficiency;

[0005]2) The rolled and expanded ring blank needs to be prepared by punching, and the final cross-sectional shape needs to be guaranteed by cutting excess dressing, so the material utilization rate is low;

[0006]3) The machining process cuts off the metal flow line, resulting in a decrease in the comprehensive mechanical properties of the ring;

[0007]4) The preparation process requires repeated heating, resulting in coarse grains, severe surface oxidation, and large energy consumption

[0008]The Chinese patent with publication number CN 101817134A discloses a method for short-flow casting-rolling composite forming of metal rings. Although the method satisfies the beneficial effects of short production process and saving energy, materials and manpower to a certain extent, the method adopts centrifugal casting ring billet, which cannot meet the processing requirements of ring parts with complex cross-sections, and the comprehensive mechanical properties of the metal ring parts produced are The performance is still not up to the requirements of extreme environments