Wear-resistant burning-loss-resistant ring block structure for outlet end of ceramic lining coal injection gun

Abstract

In view of the problems of the existing ceramic lining coal injection gun (short for spray gun), a wear-resistant and burning-loss-resistant ring block structure is welded at the outlet end of the spray gun. And the service life of the spray gun is prolonged through material optimization and structural design. The wear-resistant burning-loss-resistant ring block is made of a nickel-based high-temperature alloy material (ZG45Gr28Ni48W5) through a machining method to obtain the design size (the thickness H is 5-10 mm, the outer diameter D3 is smaller than or equal to the outer diameter of a 310S base body, the inner diameter D2 is larger than the inner diameter of the ceramic lining layer, a groove is machined in the inner end face of the ring block, and the diameter D1 of the groove is larger than the inner diameter of a 310S base body pipe. And an expansion gap is reserved for the ceramic lining layer by the height of 0.5-1mm), so that the burning loss resistance is realized. Meanwhile, the Al2O3 micro-laminated coating is prepared on the inner diameter of the ring block by adopting a coating method (or other methods), but the coating is required to be resistant to high temperature of 1400 DEG C or above), the thickness is 150 microns, and the wear resistance is realized (as shown in the figure). The ring block structure is welded to the outlet end of a spray gun through TIG welding, ERNiCrHo-3 is selected as a welding material, reasonable welding parameters and processes are selected, and postweld heat treatment is carried out (the preheating temperature ranges from 200 DEG C to 250 DEG C, the interlayer temperature is smaller than or equal to 150 DEG C, and stress relief annealing is carried out at 650 DEG C for 2 h after welding).

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature equipment protection, and particularly to an abrasion-resistant and burn-resistant structure at the outlet end of a ceramic-lined coal injection gun (hereinafter referred to as: gun), and is particularly applicable to a coal injection gun with 310S stainless steel lining Al 2 O 3 ceramics. Background Art

[0002] At present, the outlet ends of the vast majority of guns are exposed to the erosion of high-temperature pulverized coal particle gas flow (such as above 1200 °C) for a long time, resulting in the following problems: 1. Limitations of the 310S stainless steel matrix: Although it has certain high-temperature resistance (1050 °C), it is prone to oxidation and creep under long-term thermal cycling, resulting in structural deformation. Abnormalities in the blast furnace and improper operation cause burn damage to the outlet end of the gun. 2. Vulnerability of the ceramic lining: Al 2 O 3 ceramics have high brittleness. Under the action of thermal stress or pulverized coal particle gas flow, a thermal stress concentration area is easily formed at the outlet end of the ceramic coal injection gun, causing damage to the end ceramics. 3. At present, there are also a few guns with a retaining ring added at the outlet end, but mainly to prevent the displacement of the inner ceramic layer at high temperature. The anti-burn and wear resistance are poor, and the performance requirements in a high-temperature erosion environment cannot be guaranteed, shortening the service life of the gun. Summary of the Invention

[0003] In view of the problems existing in the existing guns, a wear-resistant and burn-resistant ring block structure is provided and welded at the outlet end of the gun. Through material optimization and structural design, the service life of the gun is extended.

[0004] 1. Selection of ring block material:

[0005] A nickel-based superalloy material (ZG45Gr 28 Ni 48 W 5 ) is used, with Ni≥48%, Gr≥28, W≥5. Its characteristics include: high-temperature strength (tensile strength ≥ 200 MPa at 1000 °C), oxidation resistance (oxidation weight gain < 1 mg / cm 2 .h) at 1000 °C, and the thermal expansion coefficient is close to 310S (14.5×10 -6 / °C, matching the matrix to reduce stress). The inner diameter coating of the ring block is selected as a high-temperature resistant nano-level Al 2 O 3 coating, or other coating materials with the same performance (high-temperature resistant above 1400 °C) can also be selected.

[0006] 2. Structural design:

[0007] Geometric parameters of the ring block: ( Figure 1) The thickness H is 5 - 10 mm, the outer diameter D3 is less than or equal to the outer diameter of the 310S base body, the inner diameter D2 is greater than the inner diameter of the ceramic lining layer, and a groove is machined on the inner end face of the ring block. The groove diameter D1 is greater than the inner diameter of the 310S base body tube. A swelling gap of 0.5 - 1 mm in height is reserved for the ceramic lining layer.

[0008] Welding process: TIG welding is adopted, the welding consumable is ERNiCrMo - 3, the preheating temperature is 200 - 250 °C, the interlayer temperature ≤ 150 °C, and stress relief annealing is carried out at 650 °C × 2 h after welding.

[0009] Coating process: The Al 2 O 3 micro - laminated coating with a thickness of about 150 μm is prepared on the inner diameter of the ring block by the coating method. Other methods can also be used to achieve this. Description of the drawings

[0010] Figure 1 : Wear - resistant and anti - burn - out ring block structure: 1 is the ring block, 2 is the wear - resistant coating

[0011] Figure 2 : Welding sectional view of the gun outlet end and the wear - resistant and anti - burn - out ring block structure. 3 is the wear - resistant and anti - burn - out ring block structure, 4 is the 310S base body, and 5 is the ceramic layer. Detailed implementation method

[0012] 1. Ring block processing: The nickel - based alloy (ZG45Gr 28 Ni 48 W 5 ) is precision - cast into a ring shape and then machined to the designed dimensions by mechanical means or directly machined to the designed dimensions from a bar stock. Sandblasting and decontamination treatments are carried out on the inner and outer surfaces of the ring block.

[0013] 2. Welding preparation: TIG welding is adopted, the current is 90 - 110 A, the voltage is 12 - 14 V, and the welding speed is 8 - 10 cm / min.

[0014] 3. Post - welding treatment: After slow cooling to room temperature, annealing is carried out at 650 °C × 2 h, and then air - cooling is carried out after furnace cooling to 300 °C.

[0015] 4. The Al 2 O 3 micro - laminated coating with a thickness of about 150 μm is prepared on the inner surface of the ring block by the coating method. Other methods can also be used to achieve this.

Claims

1. A wear-resistant and burn-resistant ring block structure for the outlet end of a ceramic lined coal injection gun (hereinafter referred to as: injection gun) is characterized by: The ring block structure material is made of nickel-based high-temperature alloy (ZG45Gr 28 Ni 48 W5) The inner diameter coating of the ring block can be made of high temperature resistant nano-grade Al2O3 coating, or other coating materials with equivalent performance (high temperature resistant above 1400°C) can be selected. The wear resistance and burning resistance of the ring block structure are guaranteed.

2. According to claim 1, in order to achieve welding with the outlet end of the spray gun, it is characterized in that The structural design ensures that:

1. Ring block geometric parameters: thickness 5-10mm, outer diameter less than or equal to the outer diameter of 310S substrate, inner diameter greater than the inner diameter of the ceramic lining, groove machined on the inner end face of the ring block, the groove diameter is greater than the inner diameter of the 310S substrate tube, and the height is 0.5-1mm to reserve expansion gap for the ceramic lining.

2. Welding process: TIG welding is adopted, the welding material is ERNiCrMo-3, the preheating temperature is 200-250℃. The interlayer temperature is ≤150℃, and stress relief annealing is performed at 650℃×2h after welding.

3. Coating process: The Al2O3 micro-laminated coating is prepared on the inner diameter of the ring block by coating method, with a thickness of about 150μm (other methods can also be used to achieve this).

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