What type of steel grit is used for sandblasting the interior and exterior of pressure vessels?

　　In the field of metalworking and surface treatment, sandblasting is a commonly used surface cleaning and pretreatment method. It is particularly suitable for rust removal, decontamination, and coating adhesion enhancement on the interior and exterior surfaces of pressure vessels. This article will discuss the types of steel grit commonly used for sandblasting the interior and exterior of pressure vessels and the criteria for selecting them.

　　1. Basic Characteristics of Steel Grit

　　Steel grit is a sandblasting and rust removal material made from high-carbon steel. It offers advantages such as high hardness, excellent wear resistance, and low cost. Steel grit undergoes heat treatment processes such as quenching and tempering, resulting in excellent physical and mechanical properties. During sandblasting, steel grit effectively removes rust, oxides, and old coatings from metal surfaces, while also enhancing surface roughness and improving coating adhesion.

　　2. Steel Grit Types and Classifications

　　Steel grit can also be categorized into spherical, conical, cylindrical, and angular shapes based on shape and hardness.

　　Each of these different types of steel grit has its own application:

　　Spherical steel grit: High hardness and excellent wear resistance, suitable for surface treatment, rust removal, cleaning, and other fields.

　　Conical steel grit: Moderate hardness, suitable for various surface treatment requirements, such as bird's-eye and contour methods.

　　Cylindrical steel grit: Lower hardness, suitable for surface treatment of thin plates and metal pipes.

　　Angular steel grit: Suitable for surface treatment of deep rust, scratches, and heavy rust layers.

　　Steel grit comes in a variety of grades, each representing different characteristics and applications.

　　Common steel grit grades and their meanings are as follows:

　　GP steel grit: General steel grit, suitable for sandblasting in casting, forging, and steel structures.

　　GL steel grit: Low-iron steel grit, suitable for sandblasting tools such as grinding wheels and cutting discs.

　　GH steel grit: High-iron steel grit, suitable for sandblasting automotive instrument panels and mechanical equipment. The higher iron content enhances the sandblasting effect.

　　Ultra-high iron steel grit: With a higher iron content, it's suitable for sandblasting heavy structures such as steel plates, pressure vessels, and pipelines.

　　III. Selection of Steel Grit for Internal and External Sandblasting of Pressure Vessels

　　Selecting the appropriate steel grit is crucial for sandblasting the internal and external surfaces of pressure vessels. Here are some selection criteria:

　　Material and Surface Requirements: Select the appropriate steel grit based on the material and surface requirements of the pressure vessel. For example, for materials such as stainless steel and aluminum alloy, choose steel grit with a higher hardness to ensure optimal treatment results.

　　Rust and Decontamination Capability: Ensure the selected steel grit effectively removes rust and dirt from the metal surface without causing excessive damage to the metal substrate.

　　Coating Adhesion: The purpose of sandblasting is to enhance coating adhesion, so the selected steel grit should create a certain degree of roughness to improve coating adhesion.

　　Cost Considerations: While ensuring optimal treatment results, consider the cost of the steel grit and choose the most cost-effective product.

　　When sandblasting the internal and external surfaces of pressure vessels, the selection of steel grit should comprehensively consider factors such as material, treatment requirements, rust removal capacity, coating adhesion, and cost. Different types of steel grit have their own characteristics and applications. Choosing the right grit is crucial for ensuring effective and efficient sandblasting.

　　Through scientific selection and appropriate sandblasting techniques, we can effectively improve the surface quality of pressure vessels, enhance their corrosion resistance, and improve their service life, providing a strong guarantee for the safety and efficiency of industrial production.