Method for cleaning iron ladle sand on surface of steel casting

Abstract

The invention discloses a method for cleaning iron ladle sand on the surface of a steel casting. The method comprises the following steps that S1, a natural gas flame gun and round steel are prepared; s2, a gun head of a flame gun is aligned to the iron ladle sand part, the flame gun is ignited, and round steel is placed at the flame position to be molten into a small molten pool; s3, the small molten pool dissolves the corresponding iron-clad sand, and then the dissolved iron-clad sand is blown and stripped from the surface of the steel through high-pressure oxygen; s4, if the dissolved matters are more, loosening by using an iron shovel while purging to prevent secondary iron-clad sand formed by adhesion; the iron ladle sand on the cast steel surface can be rapidly cleaned, and the working efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of forging, in particular to a method for cleaning iron-encrusted sand on the surface of a steel casting. Background Art

[0002] Casting defects of steel castings include cracks, shrinkage cavities, looseness, slag inclusions, sand inclusions, iron-coated sand, etc. The causes and treatment methods of each defect are different. For surface iron-coated sand defects, they are often due to raw materials, processes, operations, etc., such as excessively high pouring temperature, long pouring time, insufficient refractoriness of original sand, low or uneven compactness of sand molds or sand cores, coarse original sand particle size, poor quality of sand mold or sand core coatings, uneven coating, etc., resulting in sticky sand (iron-coated sand) on the surface of the casting, especially at the hot node R of the casting and the entrance of the inner runner.

[0003] Iron-coated sand is produced on the surface of steel castings. For casting surfaces that are not processed, the surface quality will be affected, and delivery requirements will not be met, which will affect delivery. For casting surfaces that need to be processed, the surface iron-coated sand is difficult to process due to its high hardness. Therefore, the iron-coated sand on the surface of the casting should be cleaned before completion. The iron-coated sand on the surface of the casting is a low-melting-point compound generated by the interaction of metal oxides and quartz sand. It has a very high hardness and cannot be removed by sandblasting, shot blasting, grinding with a grinder, etc. A new method must be sought to clean the iron-coated sand on the surface of the casting to meet the surface quality requirements of steel castings. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and to provide a method for cleaning the iron-encrusted sand on the surface of a steel casting.

[0005] The specific scheme of the present invention is as follows: a method for cleaning iron-encrusted sand on the surface of a steel casting, comprising the following steps: S1. Prepare natural gas flame gun and round steel; S2. Aim the tip of the flame gun at the iron-clad sand part, light the flame gun, and place the round steel at the flame to melt it into a small molten pool; S3, the small molten pool dissolves the corresponding iron-clad sand, and then uses high-pressure oxygen to blow the dissolved iron-clad sand off the surface of the steel; S4. If there are a lot of dissolved matter, loosen it with a shovel while blowing to prevent it from sticking and forming secondary iron-coated sand.

[0006] Furthermore, the method further includes step S5, grinding the surface of the steel material after completely cleaning all the iron-encrusted sand.

[0007] Furthermore, the step S2 is specifically as follows: check whether the oxygen and natural gas pressures meet the pressure requirements, and if so, open the oxygen and natural gas pipeline valves; aim the gun head at the iron-encased sand part, turn on the natural gas and oxygen knobs on the flame gun in turn, ignite the natural gas and oxygen, and place the round steel in the center of the flame at the same time, melt the round steel, quickly form a small molten pool, dissolve the iron-encased sand, and peel off the casting body.

[0008] Furthermore, in step S1, the diameter of the round steel is 8-10 mm.

[0009] Furthermore, in step S2, the natural gas pressure is 0.08-0.10 MPa, and the oxygen pressure is 0.8-1.0 MPa.

[0010] The working principle of the present invention is as follows: The main component of natural gas is methane, which burns fully with the help of oxygen. Due to the high calorific value of natural gas, a large amount of heat is generated instantly, which quickly melts the round steel to form a small molten pool, dissolving the low-melting-point compound iron-coated sand. The dissolved material is then stripped from the casting body under the purge of high-pressure oxygen, thereby removing the high-hardness iron-coated sand. Finally, the surface is polished with a grinding wheel machine to obtain a steel casting that meets the surface quality requirements.

[0011] Compared with the prior art, the present invention has the following beneficial effects: the present invention dissolves the low-melting-point compound iron-coated sand by the heat generated by the combustion of high-calorific-value natural gas, and then peels the dissolved matter off the casting body under the purge of high-pressure oxygen provided by the flame gun, thereby removing the iron-coated sand on the casting surface to meet the casting surface standard requirements. The entire processing process is faster and the processing efficiency is greatly improved. DETAILED DESCRIPTION

[0012] In order to better explain the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with specific embodiments. The following embodiments are merely illustrative of the technical solution of the present invention and do not limit the present invention in any form.

[0013] This embodiment takes the produced cast steel slag pot as an example. The slag pot is made of ZG230-450. Due to various factors, iron-encrusted sand is generated at the arc R where the reinforcing ribs and the body meet, which does not meet the standard requirements. The iron-encrusted sand is cleaned according to the following steps: 1. Prepare a 10mm diameter round steel and a natural gas flame gun; 2. First, check the pressure of the oxygen and natural gas pipelines connected to the flame gun. The pressures of oxygen and natural gas are 1.0MPa and 0.10MPa respectively, which meet the pressure requirements. Then open the valves of the oxygen and natural gas pipelines; 3. Aim the tip of the flame gun at the iron-clad sand part, turn on the natural gas and oxygen knobs on the flame gun in turn, ignite the natural gas and oxygen, and place the round steel in the center of the flame. The flame gun quickly melts the round steel and forms a small molten pool on the surface of the casting. The temperature of the small molten pool is higher than the melting point of the iron-clad sand, which dissolves it. After dissolving, it is automatically peeled off from the casting body under the action of the high-pressure oxygen purge of the flame gun; 4. Use a shovel to loosen the sand while blowing to prevent the dissolved matter from adhering again and forming secondary iron-coated sand; 5. Thoroughly clean the dissolved substances on the surface and grind the surface with a grinder.

Claims

1. A method for cleaning iron-encrusted sand on the surface of steel castings, characterized in that: The following steps are involved: S1. Prepare natural gas flame gun and round steel; S2. Aim the tip of the flame gun at the iron-clad sand part, light the flame gun, and place the round steel at the flame to melt it into a small molten pool; S3, the small molten pool dissolves the corresponding iron-clad sand, and then uses high-pressure oxygen to blow the dissolved iron-clad sand off the surface of the steel; S4. If there are a lot of dissolved matter, loosen it with a shovel while blowing to prevent it from sticking and forming secondary iron-coated sand.

2. The method for cleaning iron-encrusted sand on the surface of a steel casting according to claim 1, characterized in that: The method further comprises step S5 of grinding the surface of the steel material after thoroughly cleaning all the iron-encrusted sand.

3. The method for cleaning iron-encrusted sand on the surface of a steel casting according to claim 1, characterized in that: The step S2 specifically includes: checking whether the oxygen and natural gas pressures meet the pressure requirements, and if so, opening the oxygen and natural gas pipeline valves; aiming the gun head at the iron-encased sand part, turning on the natural gas and oxygen knobs on the flame gun in turn, igniting the natural gas and oxygen, and placing the round steel in the center of the flame at the same time, the round steel melts, quickly forming a small molten pool, and the iron-encased sand dissolves and is peeled off from the casting body.

4. The method for cleaning iron-encrusted sand on the surface of a steel casting according to claim 1, characterized in that: The diameter of the round steel in step S1 is 8-10 mm.

5. The method for cleaning iron-encrusted sand on the surface of a steel casting according to claim 1, characterized in that: In step S2, the natural gas pressure is 0.08-0.10 MPa, and the oxygen pressure is 0.8-1.0 MPa.