Method for preventing explosive skin of stainless steel castings during non-vacuum quenching heat treatment air cooling process

Abstract

The application discloses a method for preventing explosive skin of stainless steel castings in non-vacuum quenching and heat treatment air cooling process, which comprises: a treatment process of a whole castings non-vacuum quenching and heat treatment placing structure capable of consuming oxygen and moisture in a non-vacuum environment. The moisture on the bottom surface of the heat treatment barrel is heated and contacted with charcoal to be absorbed and reacted, and the oxygen in the heat treatment barrel is also reacted with charcoal to be absorbed, at the same time, the gas on the top surface of the heat treatment barrel is heated and can overflow from the asbestos outside the barrel cover, so that the oxygen and moisture in the non-vacuum environment are absorbed and reacted by charcoal and overflow from the heat treatment barrel through the asbestos outside while being heated and quenched, the oxygen and moisture in the non-vacuum environment are prevented from reacting with the surface of the castings to cause oxidation and explosive skin in the high-temperature environment, and the problem that the oxygen and moisture in the non-vacuum environment cannot be consumed in the high-temperature environment and react with the surface of the castings to cause oxidation and explosive skin is solved.

Description

Technical Field

[0001] This invention relates to a method for preventing the surface of stainless steel castings from exploding during air cooling in non-vacuum quenching heat treatment, belonging to the field of casting heat treatment technology. Background Technology

[0002] For stainless steel castings obtained by casting materials such as ZG1Cr18Ni9Ti, ZG0Cr18Ni9Ti, ZG1Cr11Ni2WmoV, and ZG1Cr18Ni9Nb, when quenching heat treatment is performed in a non-vacuum environment, oxygen and moisture will be present in the environment. Under high temperature conditions, oxidation and scaling will occur during quenching heat treatment and subsequent air cooling. For example, a quenching mechanism for the production of corrosion-resistant castings disclosed in Chinese Patent Publication No. CN218989311U is as follows: a corrosion-resistant casting is placed in the placement basket. During quenching, the oxide scale that falls off will fall into the placement basket. The oxide scale can be cleaned simply by removing the placement basket.

[0003] The main reason for oxidation and peeling is that oxygen and moisture in a non-vacuum environment cannot be consumed at high temperatures and react with the surface of the casting. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a method for preventing the skin of stainless steel castings from exploding during the air cooling process of non-vacuum quenching heat treatment.

[0005] The present invention is achieved through the following technical solutions.

[0006] The present invention provides a method for preventing the stainless steel casting from exploding during the air cooling process of non-vacuum quenching heat treatment, comprising: a process of constructing a whole structure for placing the casting during non-vacuum quenching heat treatment that can consume oxygen and moisture in a non-vacuum environment.

[0007] The processing procedure is as follows:

[0008] Take a heat treatment barrel with a hollow containment space, lay a layer of charcoal on the bottom surface inside the heat treatment barrel, place the casting on the charcoal, cover the top opening of the heat treatment barrel with a lid and seal it with asbestos, forming a whole structure for non-vacuum quenching heat treatment of castings that can consume oxygen and moisture in a non-vacuum environment, heat the whole structure for quenching heat treatment, and air cool the whole structure after the quenching heat treatment is completed.

[0009] The bottom edge of the barrel lid is in close contact with the outer edge of the opening at the top of the heat treatment barrel, and the asbestos-filled seal is installed between the inner edge of the outer edge and the outer edge of the barrel lid.

[0010] A pad is placed on top of the charcoal, and a casting is placed on the pad above the charcoal, so that the casting rests on the pad.

[0011] The non-vacuum quenching heat treatment placement structure of the casting is as follows:

[0012] Heat treatment barrel, with an opening at the top and internal storage space;

[0013] Charcoal was laid on the bottom surface inside the heat treatment barrel;

[0014] A pad placed on top of the charcoal;

[0015] The casting is placed on top of the pad.

[0016] A lid is installed in close contact with the outer edge of the top of the heat treatment barrel opening, and the lid covers the top of the heat treatment barrel opening.

[0017] The asbestos is filled and sealed between the inner edge of the outer edge and the outer edge of the barrel lid.

[0018] The beneficial effects of this invention are as follows: the moisture at the bottom of the heat treatment barrel is absorbed and reacted with the charcoal when heated, and the oxygen inside the heat treatment barrel is also absorbed by the charcoal. At the same time, the gas at the top of the heat treatment barrel is heated and overflows from the asbestos through the lid. This achieves the simultaneous absorption and consumption of oxygen and moisture by the charcoal and the overflow from the heat treatment barrel through the asbestos in a non-vacuum environment during the heating and quenching heat treatment. This avoids the oxidation and peeling caused by the reaction of oxygen and moisture in the non-vacuum environment with the surface of the casting at high temperature, thus ensuring the quality of the casting after quenching heat treatment and obtaining a casting with a good surface. This solves the problem that oxygen and moisture in the non-vacuum environment cannot be consumed at high temperature and react with the surface of the casting, resulting in oxidation and peeling. Attached Figure Description

[0019] Figure 1 This is a process flow chart of the present invention;

[0020] Figure 2 This is a schematic diagram of the process placement and distribution of the present invention;

[0021] In the diagram: 1-Heat treatment barrel; 11-Barrel lid; 12-Outer edge; 2-Charcoal; 3-Plate; 4-Casting; 5-Asbestos. Detailed Implementation

[0022] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0023] like Figures 1 to 2 As shown.

[0024] This application discloses a method for preventing the outer skin of stainless steel castings during air cooling in a non-vacuum quenching heat treatment process, comprising:

[0025] Take a heat treatment barrel 1 with a hollow containment space, and lay a layer of charcoal 2 on the bottom surface inside the heat treatment barrel 1. To facilitate the placement of the casting 4, place a pad 3 on the charcoal 2, and place the casting 4 on the pad 3 above the charcoal 2, so that the casting 4 is placed on the pad 3. Use a barrel lid 11 to cover the top opening of the heat treatment barrel 1. The bottom edge of the barrel lid 11 is in close contact with the outer edge 12 of the top opening of the heat treatment barrel 1. Install asbestos 5 to fill and seal between the inner edge of the outer edge 12 and the outer edge of the barrel lid 11, thus forming an overall structure for placing castings in non-vacuum quenching heat treatment that can consume oxygen and moisture in a non-vacuum environment.

[0026] The entire casting is subjected to heat treatment by heating and quenching. After the heat treatment is completed, the entire casting is air-cooled. During air cooling, the heat inside the casting 4 causes the internal energy inside the heat treatment barrel 1 to be high, which pushes against the barrel lid 11. This forces a gap to appear at the contact point between the barrel lid 11 and the outer edge 12. Combined with the heavy external cold air pressing down on the asbestos 5 and the top surface of the barrel lid 11, the external cold air cannot enter the interior of the heat treatment barrel 1 from the asbestos 5 and the contact point between the barrel lid 11 and the outer edge 12.

[0027] During the overall heating and quenching heat treatment, the moisture at the bottom of the heat treatment barrel 1 is heated and reacts with the charcoal 2. The oxygen inside the heat treatment barrel 1 also reacts with the charcoal 2 and is absorbed. At the same time, the gas at the top of the heat treatment barrel 1 is heated and overflows from the asbestos 5 through the lid 11. This process ensures that oxygen and moisture in the non-vacuum environment are simultaneously absorbed and consumed by the charcoal 2 and overflow from the heat treatment barrel 1 through the asbestos 5. This avoids the oxidation and peeling caused by the reaction of oxygen and moisture in the non-vacuum environment with the casting surface at high temperature, thus ensuring the quality of the casting after quenching and heat treatment. This solves the problem of oxidation and peeling caused by the inability to consume oxygen and moisture in the non-vacuum environment at high temperature.

[0028] The non-vacuum quenching heat treatment placement structure of the casting is as follows:

[0029] A heat treatment container 1 with an opening at the top and internal storage space;

[0030] Charcoal 2 is laid on the bottom surface inside the heat treatment barrel 1;

[0031] The pad 3 is placed above the charcoal 2;

[0032] Casting 4 is placed above pad 3;

[0033] A lid 11 is installed in close contact with the outer edge 12 of the top opening of the heat treatment barrel 1, and the lid 11 covers the top opening of the heat treatment barrel 1.

[0034] The asbestos 5 is filled and sealed between the inner edge of the outer edge 12 and the outer edge of the barrel lid 11.

Claims

1. A method for preventing the formation of spalling on a stainless steel casting during non-vacuum quenching heat treatment air cooling, characterized by, Include: The processing procedure of the whole structure of the cast non-vacuum quenching heat treatment placement structure which can consume oxygen and moisture in non-vacuum environment; The whole structure of the cast non-vacuum quenching heat treatment placement structure, comprising: A heat treatment barrel (1) with an open top and an accommodating space inside; Charcoal (2) laid on the bottom surface inside the heat treatment barrel (1); A base plate (3) placed above the charcoal (2); A cast (4) placed above the base plate (3); A barrel cover (11) tightly contacted and installed on the extension edge (12) of the open top of the heat treatment barrel (1), covering the open top of the heat treatment barrel (1); Asbestos (5) filled and sealed between the inner surface edge of the extension edge (12) and the outer surface edge of the barrel cover (11); The processing procedure is as follows: Take the heat treatment barrel (1) with a hollow accommodating space, lay a layer of charcoal (2) on the bottom surface inside the heat treatment barrel (1), place the cast (4) on the charcoal (2), cover the open top of the heat treatment barrel (1) with the barrel cover (11) and fill and seal with the asbestos (5), to form a whole cast non-vacuum quenching heat treatment placement structure which can consume oxygen and moisture in non-vacuum environment, heat and quench the whole structure, and air cool the whole structure after the quenching heat treatment is completed; The bottom edge of the barrel cover (11) is tightly contacted with the extension edge (12) of the open top of the heat treatment barrel (1), and the asbestos (5) is filled and sealed between the inner surface edge of the extension edge (12) and the outer surface edge of the barrel cover (11); Place the base plate (3) above the charcoal (2), place the cast (4) on the base plate (3) above the charcoal (2), so that the cast (4) is placed on the base plate (3).

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