CN110457729B - Optimization method and device for semi-closed structural steel heat treatment part and shaft part - Google Patents

Abstract

The invention provides an optimization method and device for a semi-closed structural steel heat treatment part and a shaft part. The method comprises the following steps: obtaining the diameter of a solid part of the shaft part; obtaining the wall thickness of the semi-closed pipe for increasing the fabrication hole; determining the maximum equivalent circle ER of the shaft part according to the diameter and the wall thickness; and selecting the material of the shaft part according to ER of the part. The invention solves the problems that the selection of raw materials of parts is less, and the raw materials, machining cost and heat treatment cost are correspondingly increased because the hardenability size requirement of the parts is over high.

Description

Optimization method and device for semi-closed structural steel heat treatment part and shaft part

Technical Field

The invention relates to the field of heat treatment, in particular to an optimization method and device for semi-closed structural steel heat treatment parts and shaft parts.

Background

With the development of meeting the development of the aviation industry and the development of material research, advanced materials are continuously selected as design materials, and imported materials with excellent hardenability and performance are introduced for part production. At present, although most structural steels meet the strength requirements of the conventional tension rod part shown in fig. 1, the semi-closed tubular structure has low hardenability, and the actual production mostly adopts expensive steel materials with hardenability, such as 4340 imported steel materials. As a result, the material cost is greatly increased, the cost of the machine is increased, and the heat treatment cannot be carried out in the same furnace with other materials due to different parameters during heat treatment, so that the heat treatment heat frequency is increased.

Disclosure of Invention

The invention provides an optimization method and device for semi-closed structural steel heat treatment parts and shaft parts, which can improve hardenability and increase the types of selectable steel.

In a first aspect, a method for optimizing a semi-closed structural steel heat treatment part is provided, which comprises the following steps:

obtaining the diameter of a solid part of the shaft part;

obtaining the wall thickness of the semi-closed pipe with the added fabrication hole;

determining the maximum equivalent circle ER of the shaft part according to the diameter and the wall thickness;

and selecting the material of the shaft part according to ER of the part.

Further, the determining ER of the shaft part according to the diameter and the wall thickness includes:

calculating ER of the solid part through the diameter;

calculating ER of the semi-closed tube according to the wall thickness;

and selecting the larger ER of the solid part and the ER of the semi-closed tube as the ER of the shaft part.

In a second aspect, an optimization device for a semi-closed structural steel heat treatment part is provided, which comprises:

the obtaining module is used for obtaining the diameter of the solid part of the shaft part; the shaft parts comprise solid parts and semi-closed pipes added with process holes; obtaining the wall thickness of the semi-closed pipe with the added fabrication hole;

the determining module is used for determining the maximum equivalent circle ER of the shaft part according to the diameter and the wall thickness;

and the selection module is used for selecting the material of the shaft part according to the ER of the part.

Further, the determining module comprises:

a first calculation unit for calculating ER of the solid portion from the diameter;

a second calculating unit for calculating ER of the semi-closed tube according to the wall thickness;

and the selecting unit is used for selecting the larger ER of the solid part and the ER of the semi-closed tube as the ER of the shaft part.

In a third aspect, a shaft part is provided and divided into a solid part and a semi-closed tube, wherein a process hole penetrating through the shaft part along the diameter direction of the shaft part is formed at the joint of the semi-closed tube and the solid part.

Further, the fabrication hole is drilled by a drilling machine.

Further, the closed surface of the semi-closed tube is a part of the interface surface of the semi-closed tube and the solid part.

Further, the inner part of the semi-closed pipe is communicated with the process hole.

Furthermore, the shaft part is a pull rod handle with a semi-closed hole.

The increase of the heat treatment process hole avoids the situation that the part only meets the requirement of surface strength, and the part of the core part which does not reach the full-hardening size range can not meet the requirement of the design strength and hardness of the part. And the process holes are added, the maximum equivalent circle (ER) value of the heat treatment of the part is reduced, and the material selection range is expanded. According to the requirements of performance parameters such as strength and the like, conventional materials such as 4130 and 30CrMnSiA and the like which have the specifications and are stored can be selected to manufacture parts, so that the waste caused by large initial ordering amount of steel parts is avoided, and meanwhile, due to the application of conventional steel, machining and heat treatment can be produced along with common parts, so that the investment of the process cost of raw materials, machining, heat treatment and the like is reduced.

Drawings

The invention comprises 2 figures, which are described as follows:

FIG. 1 is a schematic view of a prior art drawbar arrangement;

FIG. 2 is a schematic diagram of a maximum equivalent circle calculation method for a solid section;

FIG. 3 is a schematic diagram of a maximum equivalent circle calculation method for a tubular section;

FIG. 4 is a front view of an axial component provided by the present invention;

FIG. 5 is a top view of an axial feature provided by the present invention.

Detailed Description

The invention provides an optimization method of a semi-closed structural steel heat treatment part, the hardenability size of the heat treatment part of the method is related to the maximum equivalent circle (ER) of the heat treatment part, wherein the calculation method of a simple solid section is shown in figure 2; the equivalent circle of the tubular section is calculated as follows as shown in fig. 3.

Within the allowable range of process strength, the semi-closed part is added with a process hole for quenching and cooling, and the calculated ER value can be reduced by at least more than 50%.

The invention provides an optimization method of a fabrication hole for improving hardenability, which enables the material selection of parts not to be limited to 4340 imported steel, can select 4130, 30CrMnSiA and other materials to manufacture the parts, has negligible influence on strength due to the increase of the fabrication hole, can meet the maximum strength requirement of the parts, can meet the maximum limit size requirement of heat treatment in the national military standard, and reduces the investment of the process cost of raw materials, machining, heat treatment and the like.

The invention relates to an optimization method of a semi-closed structural steel heat treatment part, which improves the hardenability of a semi-closed hole by increasing a fabrication hole mode by combining the accompanying drawings:

in the embodiment, a handle shaft for aviation is taken as an example of a shaft part, the handle shaft is provided with a semi-closed hole, the strength requirement is sigma b =1103 MPa-1241 MPa, and the original part is shown in fig. 1. Calculating the ER value of the handle shaft according to the requirement of heat treatment:

ER =20mm for solid part 1;

ER =2.5 × 20mm =50mm (T =20 mm) of semi-closed tube 2;

the handle axis should be 50mm, calculated as the maximum ER.

The raw materials are selected according to the requirements of the strength and the hardenability of the handle shaft. In general, the maximum equivalent circle (ER) size of a conventional steel material is shown in table 1 when the required tensile strength σ b =1103MPa to 1241 MPa:

TABLE 1

Serial number	Alloy (II)	Maximum equivalent circle (ER) size mm
			1	30CrMnSiNi2A	80
2	18CrMn2MOBA	80
			3	4340	63.5
4	8740	20.3
			5	4140	25.4
6	30CrMnSiA	25
			7	40CrNiMoA	35
8	12Cr2Ni4A	30
			9	12CrNi3A	25
10	4130	12.7

Therefore, the raw materials of the handle shaft can only be selected from ultra-high strength steel or imported structural steel such as 30CrMnSiNi2A, 18CrMn2MoBA, 4340 and the like.

However, with the addition of the heat treatment process holes according to FIGS. 4-5, the ER value of the handle shaft can be calculated as follows in terms of the through holes:

ER =20mm for the solid part, no change.

ER =2.0 × 7mm =14mm for the semi-closed tube (calculated as wall thickness T, T = (20-6)/2 =7 mm).

The handle axis should be 20mm calculated as maximum ER. 60% lower than the previous 50mm.

As can be seen from the results, the steel material for the handle shaft can not satisfy the requirements except for the 4130 structural steel in Table 1, and the hardenability of the rest materials can satisfy the requirements of the handle shaft.

The invention overcomes the problems that the selection of raw materials of parts is less and the raw materials, machining cost and heat treatment cost are correspondingly increased due to the over-high requirement on the hardenability size of the parts.

Claims (2)

1. An optimization method for a semi-closed structural steel heat treatment part is characterized by comprising the following steps:

obtaining the diameter of a solid part of the shaft part;

obtaining the wall thickness of the semi-closed pipe for increasing the fabrication hole;

determining the maximum equivalent circle ER of the shaft part according to the diameter and the wall thickness;

selecting the material of the shaft part according to ER of the part;

determining ER of the shaft part according to the diameter and the wall thickness comprises the following steps:

calculating ER of the solid part through the diameter;

calculating ER of the semi-closed tube according to the wall thickness;

and selecting the larger ER of the solid part and the ER of the semi-closed tube as the ER of the shaft part.

2. An optimization device for semi-closed structural steel heat treatment parts is characterized by comprising:

the obtaining module is used for obtaining the diameter of the solid part of the shaft part; the shaft parts comprise solid parts and semi-closed pipes added with process holes; obtaining the wall thickness of the semi-closed pipe for increasing the fabrication hole;

the determining module is used for determining the maximum equivalent circle ER of the shaft part according to the diameter and the wall thickness;

the selection module is used for selecting the material of the shaft part according to the ER of the part;

the determining module comprises:

a first calculation unit for calculating ER of the solid portion from the diameter;

a second calculation unit for calculating ER of the semi-closed tube according to the wall thickness;

and the selecting unit is used for selecting the larger ER of the solid part and the ER of the semi-closed tube as the ER of the shaft part.

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