阅读说明：本技术 一种合金结构钢扩散段壳体待胶接表面的毛化方法 (Roughening method for surface to be bonded of alloy structural steel diffusion section shell ) 是由 陈军 王勇 张之翎 崔佳垠 陆韡 王学峰 朱立坚 李睿 强锦霖 赵亦东 钟茵 于 2019-11-20 设计创作，主要内容包括：本发明公开了一种合金结构钢扩散段壳体待胶接表面的毛化方法,根据GB/T7124-2008准备合金结构钢标准试样；用酒精对合金结构钢的标准试样待毛化面进行清洗、晾干；通过激光毛化设备,选择特定的毛化点面密度、脉冲能量、脉冲时间间隔、单脉冲能量数量、激光束中轴线与坑的法线间的夹角、激光束离焦量等参数对标准试样待毛化面进行定量的激光毛化平；对激光毛化后的标准试样用胶粘剂进行胶接,胶接完成后用压块工装进行固化24小时；按上述步骤在调整激光毛化参数后,重新进行标准试样的激光毛化、胶接、测试。该发明适用于中、小型固体火箭发动机扩散段壳体待粘接表面的毛化处理,有效提高扩散段壳体与粘接剂之间的结合强度。(The invention discloses a roughening method for a surface to be bonded of a diffusion section shell of alloy structural steel, which comprises the following steps of preparing a standard sample of the alloy structural steel according to GB/T7124-2008; cleaning and airing a surface to be roughened of a standard sample of the alloy structural steel by using alcohol; selecting parameters such as specific texturing point surface density, pulse energy, pulse time interval, single pulse energy quantity, an included angle between a central axis of a laser beam and a normal line of a pit, defocusing amount of the laser beam and the like to carry out quantitative laser texturing leveling on a surface to be textured of a standard sample through laser texturing equipment; adhering the standard sample subjected to laser texturing by using an adhesive, and curing for 24 hours by using a pressing block tool after the adhering is finished; and after the laser texturing parameters are adjusted according to the steps, the laser texturing, the gluing and the testing of the standard sample are carried out again. The method is suitable for texturing the surface to be bonded of the diffusion section shell of the medium and small solid rocket engines, and effectively improves the bonding strength between the diffusion section shell and the adhesive.)

1. A roughening method for a surface to be bonded of an alloy structural steel diffusion section shell is characterized by comprising the following steps:

preparing a standard sample of 30CrMnSiA alloy structural steel according to the national standard GB/T7124-2008 'determination of tensile shear strength of adhesive';

step two, cleaning and airing a surface to be roughened of a standard sample of the 30CrMnSiA alloy structural steel by using alcohol;

selecting specific parameters to carry out quantitative laser texturing on the surface to be textured of the standard sample through laser texturing equipment;

step four, performing glue joint on the standard sample subjected to laser texturing, and standing and curing after the glue joint is completed;

step five, performing a shear tensile test on the standard sample after the glue joint, and testing the tensile shear strength of the standard sample after the glue joint;

and step six, if the tensile shear strength of the standard sample does not meet the design index requirement, the laser texturing, the bonding and the testing of the standard sample are carried out again after the laser texturing parameters are adjusted according to the steps, and if the tensile shear strength of the standard sample meets the design index requirement, the same laser texturing parameters are selected to carry out the laser texturing on the bonding surface of the diffusion section shell to be bonded.

2. The method for roughening the surface to be glued of the alloy structural steel diffusion section shell according to claim 1, wherein in the third step, the parameters comprise: the surface density of the textured points, pulse energy, pulse time interval, the number of single pulse energies, the inclination angle of the laser beam and the defocusing amount of the laser beam.

3. The method for roughening the surface to be bonded of the alloy structural steel diffuser section shell according to claim 1, wherein the laser roughened object is a thin-walled rotating member having a wall thickness of 3mm or less.

4. The method for roughening the surface to be bonded of the diffusion section shell of alloy structural steel according to claim 1, wherein in the fourth step, the standard sample after laser texturing is bonded by using an adhesive, and after the bonding is completed, the standard sample is left to stand and cure for 24 hours.

5. The method for roughening the surface to be bonded of the alloy structural steel diffuser section shell according to claim 4, wherein the adhesive is bonded by E-7 adhesive.

6. The method for roughening the surface to be bonded of the alloy structural steel diffuser shell according to claim 1, wherein in the sixth step, the protective tool is used for protecting the non-roughened surface of the alloy structural steel diffuser shell in the laser roughening process.

Technical Field

The invention relates to the field of surface treatment, in particular to a method for roughening a surface to be bonded of a diffusion section shell of alloy structural steel, which is suitable for roughening the surface to be bonded of the diffusion section shell of a medium and small solid rocket engine.

Background

The diffusion section assembly in the solid rocket engine is formed by cementing diffusion section shell parts made of alloy structural steel and non-metal heat-insulating layer parts. The bonding strength between the adhesive for bonding and the non-metallic heat insulating layer is higher than that between the adhesive and the diffuser section shell, namely the bonding strength between the adhesive and the diffuser section shell directly determines the overall bonding strength of the diffuser section assembly. The bond strength is relatively low due to the mechanical bond between the adhesive and the diffuser shell. Through changing metal material surface roughness, increase the area that splices, can effectively improve the bonding strength between diffuser shell and the binder, and then improve the whole bonding strength of diffuser subassembly.

The alloy structural steel can be used for manufacturing a diffusion section shell of a solid rocket engine, and the 30CrMnSiA is a typical one of the alloy structural steel, and the contents of alloy elements are respectively as follows: c: 0.28 to 0.35, Si: 0.9 to 1.20, Mn: 0.8-1.10, Cr: 0.8 to 1.10, Ni: less than or equal to 0.04, P: less than or equal to 0.02, S: less than or equal to 0.02.

At present, the sand blasting texturing technology is generally adopted in the production and manufacturing process of the diffusion section component of the solid rocket engine in China to change the surface roughness of the metal shell and increase the bonding area, so that the overall bonding strength of the diffusion section component is improved. However, the surface roughness of the diffusion section shell subjected to sand blasting is not uniform, and the surface appearance and microstructure of the material cannot be quantitatively controlled, so that the reliability and stability of the bonding strength of the diffusion section component are poor, and the quality reliability of the product cannot be effectively guaranteed.

Therefore, it is necessary to select a new material surface texturing technique to effectively control the surface morphology and microstructure of the diffuser shell in a quantitative manner.

Disclosure of Invention

The invention provides a roughening method for the surface to be bonded of an alloy structural steel diffusion section shell, which aims to solve the problems that the surface roughness of the surface to be bonded of the diffusion section shell is uneven in sand blasting and the surface appearance cannot be quantitatively controlled and greatly improve the overall bonding strength of a diffusion section component.

In order to overcome the defects of the prior art, the invention discloses a roughening method for the surface to be bonded of an alloy structural steel diffusion section shell, which comprises the following steps:

preparing a standard sample of 30CrMnSiA alloy structural steel according to the national standard GB/T7124-2008 'determination of tensile shear strength of adhesive';

step two, cleaning and airing a surface to be roughened of a standard sample of the 30CrMnSiA alloy structural steel by using alcohol;

selecting specific parameters to carry out quantitative laser texturing on the surface to be textured of the standard sample through laser texturing equipment;

step four, performing glue joint on the standard sample subjected to laser texturing, and standing and curing after the glue joint is completed;

step five, performing a shear tensile test on the standard sample after the glue joint, and testing the tensile shear strength of the standard sample after the glue joint;

and step six, if the tensile shear strength of the standard sample does not meet the design index requirement, the laser texturing, the bonding and the testing of the standard sample are carried out again after the laser texturing parameters are adjusted according to the steps, and if the tensile shear strength of the standard sample meets the design index requirement, the same laser texturing parameters are selected to carry out the laser texturing on the bonding surface of the diffusion section shell to be bonded.

Compared with the prior art, the invention has the advantages that:

and determining appropriate laser texturing parameters for the 30CrMnSiA alloy structural steel material, quantitatively controlling the appearance and structure of the surface to be bonded, and quantitatively controlling and effectively improving the bonding tensile shear strength between the diffusion section shell and the non-metal heat-insulating layer in the diffusion section assembly.

Drawings

FIG. 1 is a flow chart of a method for roughening a surface to be bonded of a 30CrMnSiA structural steel diffusion section shell according to an embodiment of the invention;

FIG. 2 is an illustration of the surface to be bonded of a 30CrMnSiA structural steel diffusion section shell according to an embodiment of the present invention;

fig. 3 is a design drawing of a protective tool for laser texturing of a 30CrMnSiA alloy structural steel diffusion section shell in an embodiment of the invention.

Detailed Description

The invention aims to solve the problems that the roughness of the sand blasting roughened surface of the 30CrMnSiA structural steel diffusion section shell is uneven, and the surface appearance and the microstructure can not be quantitatively controlled, so that the reliability and the stability of the bonding strength of a diffusion section component are poor.

The invention is further explained with reference to the drawings and the embodiments.

The method is implemented on a 30CrMnSiA structural steel diffusion section shell, the diameter of the diffusion section shell is phi 165.5mm, the length of the diffusion section shell is 93.9mm, and the wall thickness of a thin wall is 2 mm. The design requires that the adhesive bonding tensile shear strength of the diffusion section assembly is more than or equal to 14.7 MPa. The specific method comprises the following steps:

firstly, preparing 6 standard test samples of 30CrMnSiA alloy structural steel;

step two, cleaning and airing 6 standard sample surfaces to be roughened by alcohol;

thirdly, selecting parameters such as the surface density (1/6272) (mum 2) -1 of a texturing point, the single pulse energy of 2.0mJ, the action time interval of a single pulse of 100 muS, the number of the single pulse energy of 3, the inclination angle of a laser beam of 60 degrees and the defocusing amount of the laser beam of 1.0μm and the like through laser texturing equipment to perform laser texturing on the surfaces to be textured of 6 standard samples;

step four, performing pairwise gluing on 6 standard samples subjected to laser texturing by using E-7 glue, and standing and curing 3 groups of standard samples for 24 hours after the gluing is completed;

step five, performing a shear tensile test on the standard sample after the standard sample is bonded, wherein the tensile shear strengths of the standard sample after the standard sample is bonded are 27MPa, 26MPa and 27MPa respectively according to test 3;

and step six and step five, the tensile shear strength of the 3 groups of standard samples meets the design index requirement of being more than or equal to 14.7MPa, the same laser texturing parameters are selected to carry out laser texturing on the surface to be glued of the diffusion section shell of the 30CrMnSiA alloy structural steel in the attached drawing 2, and the protective tool shown in the attached drawing 3 is used for protecting the non-textured surface of the diffusion section shell of the 30CrMnSiA alloy structural steel in the laser texturing process.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.