Metal surface shot peening alloying process

Abstract

The invention discloses a metal surface shot peening alloying process. The metal surface shot peening alloying process comprises the following steps that firstly, a manganese steel test piece with the zinc content ranging from 0.1% o to 0.2% o and the SiC content ranging from 0.3% o to 0.5% o is cleaned; secondly, shot peening treatment is conducted through ultrasonic shot peening equipment, in the scheme, a manganese steel test piece containing specific Zn and SiC content is preferably selected to conduct ultrasonic shot peening surface strengthening, it is found that in the ultrasonic shot peening strengthening process, under the cooperation of trace Zn and SiC, the test piece is promoted to generate a large amount of slippage phenomenon on the surface or the area close to the surface, a large amount of dislocation promotes formation of a high-density dislocation area, and the high-density dislocation area is formed; in the aspect of macroscopic performance, the hardness and wear resistance of the test piece are obviously improved, and the manufacturing cost of the scheme is reduced.

Description

Technical Field

[0001] This invention relates to the field of surface strengthening technology, specifically to a shot peening alloying process for metal surfaces. Background Technology

[0002] Manganese steel is widely used in industrial equipment, and the operating environment requires this material to have good wear resistance and strength. Common research directions to improve wear resistance and strength include:

[0003] First, improve the material formula of manganese steel by adding rare earth elements, hard phases, or other components, or by combining different components, to increase the surface hardness of manganese steel and improve its wear resistance. Currently, most manganese steel products on the market that have significantly improved hardness are expensive because they contain large amounts of rare earth elements or other expensive components.

[0004] Secondly, surface strengthening technology, through subsequent shot peening and alloy layer strengthening, can improve wear resistance. Shot peening significantly improves the surface hardness of materials, but it still cannot meet further requirements. As for alloy layer strengthening, common methods include solidifying alloy powders with different component ratios onto the surface of materials or workpieces using alloying technologies such as laser, plasma, electron beam, and shot peening. However, strengthening alloy layers also suffers from high costs and is relatively complicated to operate.

[0005] In response, our company has initiated a project to further improve the wear resistance of manganese steel materials while reducing costs. Summary of the Invention

[0006] To address at least one of the aforementioned technical deficiencies, the present invention provides the following technical solution:

[0007] This application discloses a metal surface shot peening alloying process, including the following steps:

[0008] First, clean the manganese steel specimens with a zinc content of 0.1-0.2‰ and a SiC content of 0.3-0.5‰.

[0009] Second, shot peening is performed using ultrasonic shot peening equipment.

[0010] In this scheme, manganese steel specimens with specific Zn and SiC contents are selected for ultrasonic shot peening to strengthen the surface. It was found that during ultrasonic shot peening, the combination of trace amounts of Zn and SiC helps to induce a large amount of structural slip in the specimen on or near the surface. A large number of dislocations promote the formation of high-density dislocation regions, which in turn hinder dislocation movement. From a macroscopic performance perspective, the hardness and wear resistance of the specimens are significantly improved, and the manufacturing cost of this scheme is reduced.

[0011] Furthermore, the composition of the manganese steel specimen is as follows: Mn 13.3-14.2%, C 1.16-1.29%, Si 0.46-0.56%, P 0.036-0.048%, S 0.51-0.61%, SiC 0.3-0.5‰, Zn 0.1-0.2‰, with the balance being Fe, by mass.

[0012] Furthermore, the composition of the manganese steel specimen is as follows: Mn 13.7-14.0%, C 1.22-1.26%, Si 0.5-0.52%, P 0.04-0.043%, S 0.55-0.58%, SiC 0.4‰, Zn 0.15‰, with the balance being Fe. The preferred composition helps to improve the strengthening performance.

[0013] Furthermore, the parameters for ultrasonic shot peening are as follows: power 1000-4000W, current 1.0-4.0A, shot peening coverage 3-6 passes, impact gun dwell time 1-2s. Optimized parameters are used to improve strengthening performance.

[0014] Furthermore, the manganese steel specimens were treated with grinding and solvent cleaning, and then shot peening after drying.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. Based on accidental discovery, this invention found that manganese steel specimens containing specific amounts of Zn and SiC exhibit significantly improved hardness and other properties after ultrasonic shot peening, and the strengthening process is further simplified. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments.

[0018] In the following examples, the preparation of manganese steel specimens can be carried out by referring to the common melting and casting and water quenching processes. The addition of each component can be carried out by conventional technology, which will not be repeated here. During casting, SiC powder (particle size of 60-80nm) is mixed with manganese steel casting liquid by flushing. The casting temperature is 1450℃. The flushing method of adding material during the casting process is a conventional material addition technology. The specific steps and parameters can be referred to conventional methods, which will not be repeated here.

[0019] The ultrasonic shot peening device uses common models available on the market, such as the CYS series and UIT series.

[0020] For cleaning, the following method is to first polish and then rinse with solvent. Specifically, polish the surface of the specimen with sandpaper, then clean it with alcohol, and let it air dry.

[0021] For ultrasonic shot peening equipment parameter settings, such as power 3000W, current 2.5A, shot peening coverage 4 passes, impact gun dwell time 2s. Or, power 4000W, current 1.8A, shot peening coverage 2 passes, impact gun dwell time 1.5s, etc.

[0022] The following embodiments are implemented using the following process flow:

[0023] The shot peening and alloying process for metal surfaces includes the following steps:

[0024] First, clean the predetermined manganese steel specimen with sandpaper, then rinse it with alcohol and let it air dry.

[0025] Second, shot peening was performed using an ultrasonic shot peening device with the following parameters: power 3000W, current 2.5A, shot peening coverage 4 times, and impact gun dwell time 2s.

[0026] The composition ratios of the manganese steel specimens in each embodiment are shown in Table 1:

[0027] Table 1

[0028] Mn C Si P S SiC Zn Fe Example 1 13.5 1.23 0.48 0.04 0.55 0.35 0.13 margin Example 2 13.8 1.24 0.52 0.042 0.58 0.40 0.15 margin Example 3 14.1 1.16 0.47 0.036 0.52 0.34 0.13 margin Example 4 13.6 1.21 0.50 0.038 0.54 0.45 0.17 margin

[0029] Zn and SiC are expressed in per mille (‰), while the contents of other components are expressed in percent (%).

[0030] An additional control group was added, as follows:

[0031] Comparative Example 1

[0032] Compared to Example 1, the difference is that there is no subsequent ultrasonic shot peening strengthening step.

[0033] Comparative Example 2

[0034] The difference compared to Example 1 is that it does not contain the Zn component.

[0035] The product samples prepared in the above embodiments and comparative examples were tested, as shown in Table 2:

[0036] Table 2

[0037] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Hardness (HV) 840 922 853 862 135 708

[0038] As can be seen from the table above, the hardness of manganese steel containing specific components is significantly improved after ultrasonic shot peening. In response to the above phenomenon, our company found through microstructure observation that during the ultrasonic shot peening process, a large number of microstructure slip phenomena occurred in the surface or near-surface region of the manganese steel sample containing specific trace amounts of Zn and SiC. The number of slip bands increased significantly, resulting in a large number of dislocations forming high-density dislocation regions, which in turn hindered dislocation movement. This is reflected in the macroscopic properties, namely, the increase in hardness and wear resistance of the specimen.

[0039] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A shot peening alloying process for metal surfaces, characterized in that, Includes the following steps: First, clean the manganese steel specimens with a zinc content of 0.1-0.2‰ and a SiC content of 0.3-0.5‰. Second, shot peening is performed using ultrasonic shot peening equipment.

2. The metal surface shot peening alloying process as described in claim 1, characterized in that: The composition of the manganese steel specimen is as follows: Mn 13.3-14.2%, C 1.16-1.29%, Si 0.46-0.56%, P 0.036-0.048%, S 0.51-0.61%, SiC 0.3-0.5‰, Zn 0.1-0.2‰, with the balance being Fe, by mass.

3. The metal surface shot peening alloying process as described in claim 2, characterized in that: The composition of the manganese steel specimen is as follows: Mn 13.7-14.0%, C 1.22-1.26%, Si 0.5-0.52%, P 0.04-0.043%, S 0.55-0.58%, SiC 0.4‰, Zn 0.15‰, with the balance being Fe.

4. The metal surface shot peening alloying process as described in claim 1, characterized in that: The parameters for ultrasonic shot peening are as follows: power 1000-4000W, current 1.0-4.0A, shot peening coverage 3-6 passes, and impact gun dwell time 1-2s.

5. The metal surface shot peening alloying process as described in claim 1, characterized in that: The manganese steel specimens were treated by grinding and solvent cleaning, and then shot peening after drying.