阅读说明：本技术 一种变截面厚度钛合金锻件准β锻造加热方法及装置 (Quasi-beta forging heating method and device for variable-section-thickness titanium alloy forging ) 是由 王哲 冯晓艳 张帅 邓瑞刚 梁艳 蔡松 刘珂妮 刘刚伟 于 2020-12-18 设计创作，主要内容包括：本发明属于钛合金热加工领域,具体涉及一种变截面厚度钛合金锻件准β锻造加热方法及装置。该方法包括：将自由锻造荒形预热,出炉后进行保温棉包套,预热到的温度能够使保温棉包覆在自由锻造荒形上；其中,自由锻造荒形中最大加热有效厚度所在荒形部位不包套,其它部位进行全包套或部分包套,其中全包套和部分包套的规则与该部位的加热有效厚度有关；将包套后荒形进行分段加热,出炉锻造得到变截面厚度钛合金锻件。(The invention belongs to the field of titanium alloy hot working, and particularly relates to a quasi-beta forging heating method and a quasi-beta forging heating device for a titanium alloy forging with variable cross-section thickness. The method comprises the following steps: preheating the freely forged rough shape, and covering with heat-insulating cotton after discharging, wherein the preheated temperature can enable the heat-insulating cotton to be coated on the freely forged rough shape; wherein, the rough shape part with the maximum heating effective thickness in the free forging rough shape is not sheathed, other parts are fully sheathed or partially sheathed, and the rules of the fully sheathed and the partially sheathed are related to the heating effective thickness of the part; and (4) heating the sheathed rough shape in a segmented manner, and discharging and forging to obtain the titanium alloy forging with the variable cross-section thickness.)

1. A quasi-beta forging heating method for a titanium alloy forging with variable cross-section thickness is characterized by comprising the following steps:

preheating the freely forged rough shape, and covering with heat-insulating cotton after discharging, wherein the preheated temperature can enable the heat-insulating cotton to be coated on the freely forged rough shape; wherein, the rough shape part with the maximum heating effective thickness in the free forging rough shape is not sheathed, other parts are fully sheathed or partially sheathed, and the rules of the fully sheathed and the partially sheathed are related to the heating effective thickness of the part;

and (4) heating the sheathed rough shape in a segmented manner, and discharging and forging to obtain the titanium alloy forging with the variable cross-section thickness.

2. The method of claim 1, wherein the method further comprises, after tapping, prior to applying the insulation cotton wrap, the method further comprising:

calculating the ratio lambda of the heating effective thickness to the maximum heating effective thickness of each part_i；

Determining whether the part is sheathed and a sheathing mode according to the rules of full sheathing and partial sheathing;

the rule is as follows:

when lambda is_iNot less than 0.8, and the part is not sheathed;

when lambda is more than or equal to 0.4_iLess than or equal to 0.8, partially sheathing the part, wherein the part is not sheathed according to a preset size along the streamline direction of the forge piece, and sheathing the part at other positions; the preset size is related to the effective heating thickness of the part;

when lambda is_iLess than or equal to 0.4, and the part is completely sheathed.

3. Method according to claim 2, characterized in that the dimension d is preset_i＝H_i×λ_i；H_iThe effective thickness of the heating at that location.

4. The method of claim 1, wherein the heating regimes of the staged heating are, in order:

(Tβ-30～50)℃×0.3min/mm×H；

(Tβ-20)℃×0.1min/mm×H；

(Tβ-10)℃×0.1min/mm×H；

(Tβ+5)℃×0.1min/mm×H；

(Tβ+10)℃×0.1min/mm×H；

(Tβ+15)℃×0.1min/mm×H；

wherein T beta is the phase transition temperature, and H is the maximum heating effective thickness.

5. A method according to claim 1, characterized in that the preferred jacket thickness is 6 mm.

6. The utility model provides a variable cross section thickness titanium alloy forging accurate beta forges heating device which characterized in that includes:

the sheathing module is used for preheating the freely forged rough shape, and sheathing heat-preservation cotton after discharging, wherein the preheated temperature can enable the heat-preservation cotton to be coated on the freely forged rough shape; wherein, the rough shape part with the maximum heating effective thickness in the free forging rough shape is not sheathed, other parts are fully sheathed or partially sheathed, and the rules of the fully sheathed and the partially sheathed are related to the heating effective thickness of the part;

and the segmented heating module is used for carrying out segmented heating on the sheathed rough shape, and discharging and forging the rough shape to obtain the titanium alloy forging with the variable cross-section thickness.

7. The apparatus of claim 6, further comprising:

a calculation module for calculating the ratio lambda of the effective heating thickness to the maximum effective heating thickness of each part_i；

The determining module is used for determining whether the part is sheathed and the sheathing mode according to the rules of full sheathing and partial sheathing;

the rule is as follows:

when lambda is_iNot less than 0.8, and the part is not sheathed;

when lambda is more than or equal to 0.4_iLess than or equal to 0.8, partially sheathing the part, wherein the part is not sheathed according to a preset size along the streamline direction of the forge piece, and sheathing the part at other positions; the preset size is related to the effective heating thickness of the part;

when lambda is_iLess than or equal to 0.4, and the part is completely sheathed.

8. The apparatus of claim 6, wherein the heating regimes of the sectional heating are sequentially as follows:

(Tβ-30～50)℃×0.3min/mm×H；

(Tβ-20)℃×0.1min/mm×H；

(Tβ-10)℃×0.1min/mm×H；

(Tβ+5)℃×0.1min/mm×H；

(Tβ+10)℃×0.1min/mm×H；

(Tβ+15)℃×0.1min/mm×H。

wherein T beta is the phase transition temperature, and H is the maximum heating effective thickness.

Technical Field

The invention belongs to the field of titanium alloy hot working, and particularly relates to a quasi-beta forging heating method and a quasi-beta forging heating device for a titanium alloy forging with variable cross-section thickness.

Background

The titanium alloy has high specific strength, good heat resistance and corrosion resistance, can be welded, has good biocompatibility and can be widely applied to the fields of aerospace, aviation, ships, weapons, biomedicine and the like. The titanium alloy basket structure has excellent damage tolerance performance and is applied to an aviation structure titanium alloy structure, the dominant process of the basket structure is a quasi-beta forging process, the hot processing window of the forging process has strict requirements on alloy phase transition temperature, and beta grains are sensitive to heating temperature before forging.

At present, a quasi-beta forging heating system is (T beta-30-50) DEG C/0.3-0.8 min/mm, heating is carried out, then, the temperature is raised to (T beta + 10-15) DEG C/0.3-0.5 min/mm, heat preservation is carried out, for a special-shaped airplane structural part, as shown in figure 1, the section thicknesses of forged pieces are different, the heat penetration time and the heat preservation time of all sections are different greatly, and the phenomena of coarse grains and uneven tissues are easy to generate in the heating and forging processes of a beta phase region. The titanium alloy forging produced by adopting the quasi-beta forging process has the advantages that the heating time and the heating mode before forging ensure the core structure transformation and the micro-area component homogenization of the blank, and avoid the coarse beta grains. Therefore, how to finely control the forging heating temperature plays an important role in ensuring the structure uniformity of the variable-section titanium alloy forging.

Disclosure of Invention

The purpose of the invention is: a quasi-beta forging heating method for a titanium alloy forging with variable cross-section thickness TC21 is provided, so that the structural uniformity of the forging is controlled.

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

a quasi-beta forging heating method for a titanium alloy forging with a variable cross-section thickness comprises the following steps:

preheating the freely forged rough shape, and covering with heat-insulating cotton after discharging, wherein the preheated temperature can enable the heat-insulating cotton to be coated on the freely forged rough shape; wherein, the rough shape part with the maximum heating effective thickness in the free forging rough shape is not sheathed, other parts are fully sheathed or partially sheathed, and the rules of the fully sheathed and the partially sheathed are related to the heating effective thickness of the part;

and (4) heating the sheathed rough shape in a segmented manner, and discharging and forging to obtain the titanium alloy forging with the variable cross-section thickness.

Further, before the heat preservation cotton sheath is carried out after the furnace is discharged, the method further comprises the following steps:

calculating the ratio lambda of the heating effective thickness to the maximum heating effective thickness of each part_i；

Determining whether the part is sheathed and a sheathing mode according to the rules of full sheathing and partial sheathing;

the rule is as follows:

when lambda is_iNot less than 0.8, and the part is not sheathed;

when lambda is more than or equal to 0.4_iLess than or equal to 0.8, partially sheathing the part, wherein the part is not sheathed according to a preset size along the streamline direction of the forge piece, and sheathing the part at other positions; the preset size is related to the effective heating thickness of the part;

when lambda is_iLess than or equal to 0.4, and the part is completely sheathed.

Further, the predetermined dimension d_i＝H_i×λ_i；H_iThe effective thickness of the heating at that location.

Further, each section of heating system of the sectional heating is as follows in sequence:

(Tβ-30～50)℃×0.3min/mm×H；

(Tβ-20)℃×0.1min/mm×H；

(Tβ-10)℃×0.1min/mm×H；

(Tβ+5)℃×0.1min/mm×H；

(Tβ+10)℃×0.1min/mm×H；

(Tβ+15)℃×0.1min/mm×H；

wherein T beta is the phase transition temperature, and H is the maximum heating effective thickness.

Further, the thickness of the preferred thermal insulation cotton bale case is 6 mm.

A variable cross-section thickness titanium alloy forging quasi-beta forging heating device comprises:

the sheathing module is used for preheating the freely forged rough shape, and sheathing heat-preservation cotton after discharging, wherein the preheated temperature can enable the heat-preservation cotton to be coated on the freely forged rough shape; wherein, the rough shape part with the maximum heating effective thickness in the free forging rough shape is not sheathed, other parts are fully sheathed or partially sheathed, and the rules of the fully sheathed and the partially sheathed are related to the heating effective thickness of the part;

and the segmented heating module is used for carrying out segmented heating on the sheathed rough shape, and discharging and forging the rough shape to obtain the titanium alloy forging with the variable cross-section thickness.

Further, the apparatus further comprises:

a calculation module for calculating the ratio lambda of the effective heating thickness to the maximum effective heating thickness of each part_i；

The determining module is used for determining whether the part is sheathed and the sheathing mode according to the rules of full sheathing and partial sheathing;

the rule is as follows:

when lambda is_iNot less than 0.8, and the part is not sheathed;

when lambda is more than or equal to 0.4_iLess than or equal to 0.8, partially sheathing the part, wherein the part is not sheathed according to a preset size along the streamline direction of the forge piece, and sheathing the part at other positions; the preset size is related to the effective heating thickness of the part;

when lambda is_iLess than or equal to 0.4, and the part is completely sheathed.

Further, each section of heating system of the sectional heating is as follows in sequence:

(Tβ-30～50)℃×0.3min/mm×H；

(Tβ-20)℃×0.1min/mm×H；

(Tβ-10)℃×0.1min/mm×H；

(Tβ+5)℃×0.1min/mm×H；

(Tβ+10)℃×0.1min/mm×H；

(Tβ+15)℃×0.1min/mm×H；

wherein T beta is the phase transition temperature, and H is the maximum heating effective thickness.

The invention has the beneficial effects that: the heating preparation before quasi-beta forging is carried out by adopting a sheath and a sectional gradual heating mode, so that the uniform macrostructure of the variable-section titanium alloy forging can be obtained, and the method is simple, feasible and easy to operate.

Drawings

Fig. 1 is a schematic structural diagram of a profiled aircraft structural member.

FIG. 2 is a schematic diagram of a jacket of the present invention.

FIG. 3 is a schematic view of the heating regime of the present invention.

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.

A quasi-beta forging heating method for titanium alloy forgings with variable cross-section thicknesses is characterized in that different heat-preservation cotton covering modes are adopted for different cross-section sizes and shapes, and the heating and heat-preservation time is controlled in a segmented mode, wherein the cross-section shapes can be circular, rectangular, quadrilateral, octagonal and the like. The sheathing mode is related to the section thickness of the blank. The specific sheathing mode is shown in figure 2.

Assuming that the maximum heating effective thickness of the blank is H, the heating effective thickness of each part is H_iEach section is not completely wrapped, and the central reserved unwrapped part has the dimension d_i，λ_iIs the ratio of each cross-sectional thickness to the maximum cross-sectional thickness, λ_i＝H_i/H。

When lambda is_iNot less than 0.8, and no sheath;

when lambda is more than or equal to 0.4_iLess than or equal to 0.8, performing sheath covering, wherein the reserved size at the center of the sheath is d_i＝H_i×λ_i；

When lambda is_iLess than or equal to 0.4, and completely wrapping.

The forging process of forging heating system adopting sectional heating in quasi-beta forging is shown in figure 3:

example 1:

the embodiment of the invention discloses a quasi-beta forging heating method for a variable cross-section TC21 titanium alloy forging, which is further explained in detail with reference to the embodiment below, but the embodiment of the invention is not limited to the method, and mainly comprises the following steps:

the method comprises the following steps: the phase transition temperature of the TC21 titanium alloy of the furnace batch is 960 ℃ measured by adopting a quenching metallographic method.

Step two: heating the freely forged blank at 800 deg.C for 2H, taking out of the furnace, and sheathing with heat-insulating cotton according to the attached figure 1, wherein H is 300mm, H₁＝210mm，H₂120mm, so λ₂＝0.7，d₂＝210×0.7＝147mm。H₁The cross section is not sheathed by heat-insulating cotton, and the thickness of the heat-insulating cotton is 6 mm.

Step three: heating the sheathed rough shape by the following heating system:

step four: discharging and forging.

Example 2:

the embodiment of the invention discloses a quasi-beta forging heating method for a variable cross-section TC18 titanium alloy forging, which is further explained in detail with reference to the embodiment below, but the embodiment of the invention is not limited to the method, and mainly comprises the following steps:

the method comprises the following steps: the phase transition temperature of the TC18 titanium alloy of the furnace batch is 875 ℃ by adopting a quenching metallographic method.

Step two: heating the free forged blank at 700 deg.C for 2H, taking out of the furnace, and sheathing with heat-insulating cotton according to the method shown in figure 1, wherein H is 350mm, H₁＝250mm，Thus λ₁＝0.71，λ₂＝0.51，d₁＝250×0.71＝178mm，d₂180 multiplied by 0.51 multiplied by 92mm, the thickness of the heat preservation cotton is 6 mm.

Step three: heating the sheathed rough shape by the following heating system:

step four: discharging and forging.

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.