CN112872262A

CN112872262A - 300M special-shaped die forging forming method

Info

Publication number: CN112872262A
Application number: CN202011557006.0A
Authority: CN
Inventors: 张瑞丽; 夏亚东; 安苏娟; 邹龙龙
Original assignee: Shaanxi Hongyuan Aviation Forging Co Ltd
Current assignee: Shaanxi Hongyuan Aviation Forging Co Ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-06-01

Abstract

The invention belongs to the technical field of forging, and relates to a method for forming a 300M special-shaped die forging, which comprises the following steps: step one, blank making 1 fire: a tool is used for manufacturing a blank, the heating temperature is 1100 ℃, the heating coefficient is 0.3-0.5 min/mm, and the deformation is 30% -45%; step two, die forging and two-fire forming: heating at the No. 1 heating temperature of 1080 ℃, the heating coefficient of 0.3-0.5 min/mm and the deformation of 20-50 percent; heating at 1050 ℃ with the second heating temperature, wherein the heating coefficient is 0.3-0.5 min/mm, and the deformation is 20-30%; the method ensures that the forged tissue meets the technical requirements by regulating and controlling the heating specification and the deformation amount of each fire.

Description

300M special-shaped die forging forming method

Technical Field

The invention belongs to the technical field of forging, and relates to a method for forming a 300M special-shaped die forging.

Background

300M, full name: 40CrNi2Si2 MoVA. The steel is a low-alloy ultrahigh-strength steel developed by international nickel corporation in the United states in 1952, and has become the steel for landing gears with the highest strength, the best comprehensive performance, the most extensive application and the best reputation in the world. Its mechanical properties have the advantages of high strength, high transverse plasticity, high fracture toughness, excellent fatigue property and good corrosion resistance.

300M steel has good high-temperature plasticity and good forging formability, but is easy to generate coarse-grain defects in the forging process. The grain size is one of important means for controlling mechanical properties, and the generation of coarse grains can cause the remarkable reduction of the comprehensive properties of the forged piece. Therefore, the 300M steel part is forged and formed by 1-fire forging conventionally, the structural shape of the part related to the invention belongs to a special-shaped die forging (shown as a schematic diagram 1) which not only has a closed rib, a thin plate and a high platform, but also has small sizes at two ends and large size in the middle, and the special-shaped die forging is commonly used for a missile upper hook, a bomb hook, a lifting hook and the like. The conventional forging process has the problems that the die forging forming of the part is difficult, the forming is satisfied, but the physicochemical result after forging is unstable.

Disclosure of Invention

The purpose of the invention is: the method for forming the 300M special-shaped die forging solves the problems of coarse grains and unqualified mechanical properties caused by the fact that the die forging is special in shape and needs multiple times of forging.

In order to solve the technical problem, the technical scheme of the invention is as follows:

a method for forming a 300M special-shaped die forging, comprising the following steps:

step one, blank making 1 fire:

a tool is used for manufacturing a blank, the heating temperature is 1100 ℃, the heating coefficient is 0.3-0.5 min/mm, and the deformation is 30% -45%;

step two, die forging and two-fire forming:

heating at the No. 1 heating temperature of 1080 ℃, the heating coefficient of 0.3-0.5 min/mm and the deformation of 20-50 percent;

the 2 nd heating temperature is 1050 ℃, the heating coefficient is 0.3-0.5 min/mm, and the deformation is 20-30%.

The frock is the child mould, includes: the die cavity of the upper die and the die cavity of the lower die form a preset cavity with a special-shaped section; and the shape of the cavity of the upper die and the shape of the cavity of the lower die are matched with the shape of the special-shaped die forging.

Preferably, the step one heating coefficient is 0.5 min/mm.

Preferably, the step one deformation is 40%.

Preferably, the heating coefficient in the second step 1 is 0.5 min/mm; the deformation amount was 45%.

Preferably, the heating coefficient in the second step 2 fire is 0.5 min/mm; the deformation amount was 28%.

The invention has the beneficial effects that:

the invention ensures the consistency of the blank through the design and the use of the special tool, thereby ensuring the forming of the die forging. The heating specification and the deformation of each heating time are adjusted and controlled, so that the forged tissue meets the technical requirements. The texture grain size reaches 5 grade or above 5 grade, and the performance data reaches the numerical value requirement of table 1.

TABLE 1

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the embodiment of the present invention will be briefly explained. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic view of a profile member according to the present invention, wherein fig. 1(a) is a left side view, fig. 1(b) is a front view, and fig. 1(c) is a right side view;

FIG. 2 is a schematic view of an upper tire mold;

FIG. 3 is a schematic view of the upper tire mold.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Features of various aspects of embodiments of the invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. The following description of the embodiments is merely intended to better understand the present invention by illustrating examples thereof. The present invention is not limited to any particular arrangement or method provided below, but rather covers all product structures, any modifications, alterations, etc. of the method covered without departing from the spirit of the invention.

In the drawings and the following description, well-known structures and techniques are not shown to avoid unnecessarily obscuring the present invention.

A part is made of 300M materials, is used for a hook on a missile and is a special-shaped part in appearance. The parts have requirements on the organization and the mechanical property: (the grain size requires grade 5 or finer; the mechanical property standards are shown in Table 1). The forging heating method of the invention is adopted: in order to obtain a die forging with qualified size and easy forming, a bar stock with the specification phi 60 is firstly processed to the blank size by using a special forming die (shown in figures 2 and 3).

The shape and the bending angle are kept consistent after the blank is manufactured. The surface quality and the qualified product rate of the size of all forgings after die forging reach 100 percent.

After blank manufacturing, carrying out die forging forming on a die forging hammer of die forging 3T, finishing the die forging by two fires, wherein the 1 st fire deformation is 45 percent, the 2 nd fire deformation is 28 percent, the finish forging temperature is more than or equal to 850 ℃, and the heating specification is as follows: heating temperature of No. 1 fire is 1080 deg.C, heating coefficient is 0.5 min/mm; the heating temperature of the No. 2 fire is 1050 ℃, and the heating coefficient is 0.5 min/mm. After die forging, the forge piece is subjected to heat treatment and anatomical examination, the mechanical property is low, the structure is uniform, no coarse crystal exists, and all the mechanical properties (the grain size is 6 grade; the data of the mechanical properties are shown in table 2) meet the standard requirements.

TABLE 2

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the present invention, and these modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for forming a 300M special-shaped die forging is characterized by comprising the following steps: the method comprises the following steps:

step one, blank making 1 fire:

step two, die forging and two-fire forming:

2. The method of claim 1, wherein: the frock is the child mould, includes: the die cavity of the upper die and the die cavity of the lower die form a preset cavity with a special-shaped section; and the shape of the cavity of the upper die and the shape of the cavity of the lower die are matched with the shape of the special-shaped die forging.

3. The method of claim 1, wherein: the heating coefficient of the first step is 0.5 min/mm.

4. The method of claim 1, wherein: step one deflection was 40%.

5. The method of claim 1, wherein: in the second step, the heating coefficient in the fire is 0.5min/mm in the first step.

6. The method of claim 1, wherein: step two, the heating coefficient in the fire of step 2 is 0.5 min/mm.

7. The method of claim 1, wherein: step two, the 1 st fire deformation amount is 45 percent.

8. The method of claim 1, wherein: step two, the 2 nd fire deformation is 28%.