Steel shot blasting is an essential process in manufacturing and maintenance due to its efficiency, effectiveness in surface preparation, and the quality enhancement it brings to the final product. Today, we will learn the definition, application, and the vital importance of steel shot blasting in industries.
1.1 Definition of Steel Shot Blasting
Steel shot blasting is an abrasive blasting process used to clean metal surfaces from rust, scale, and other contaminants. The grinding medium used in this process is steel shot, which is small and round particle made of steel.
1.2 Steel Shot vs Stainless Steel Shot
During the process of blasting, there are two commonly used metallic abrasive media: steel shot and stainless steel shot. Each has distinct characteristics and is suitable for specific applications. Here is the comparison between steel shot and stainless steel shot.
Stainless Steel Shot
Made from carbon steel.
Made from stainless steel (contains chromium, nickel, etc.).
Generally harder, prone to rust in high-moisture environments.
slightly less hard than regular steel shot.
Used in general blasting, rust removal, surface preparation, shot peening.
Ideal where ferrous contamination must be avoided;
used in stainless steel fabrications.
More cost-effective, widely available in various sizes and grades.
less commonly available.
Can leave iron traces, leading to rust; recyclable.
Less likely to cause ferrous contamination;
recyclable but may wear out faster.
Aggressive cleaning, suitable for rough surface profile.
Cleaner finish, less risk of imparting rust;
smoother finish on non-ferrous metals.
2.1 Different Types of Steel Shots and Applications
According to the specific applications, steel shot for blasting comes in various types, which vary in size, hardness, and shape. The primary types of steel shot used in blasting are categorized by these characteristics:
Based on size:
Small Steel Shot (e.g., S70, S110):
Ideal for cleaning thin or delicate metal surfaces without causing warping or damage.
Used for finishing and smoothing surfaces, creating a uniform, polished appearance.
Medium Steel Shot (e.g., S230, S280):
Commonly used for general blasting tasks.
Suitable for cleaning and preparing surfaces for coating, and removing medium levels of rust and paint.
Large Steel Shot (e.g., S460, S550, S780):
Effective for heavy-duty blasting jobs.
Used for removing heavy rust, scale, and old coatings from thick and robust metal surfaces.
Based on Hardness:
General Purpose (GP) Steel Shot:
Standard hardness, versatile for various blasting needs.
Commonly used for descaling and surface preparation.
Hard (H) Steel Shot:
Higher hardness, more aggressive than GP.
Suitable for tougher jobs like removing heavy scale.
Extra Hard (EH) Steel Shot:
Very high hardness, used for the most demanding applications.
Ideal for surface etching and creating a rough profile for better coating adhesion.
2.2 How to Choose the Right Type of Steel Shot for Blasting
Sandblasting object evaluation:
Evaluate the hardness of the material you want to sandblasting. To avoid surface damage, softer metals require softer and smaller steel shots to be sandblasted. And harder metals can withstand larger and harder steel shots. For precision or delicate parts, choose smaller and less abrasive steel shots.
Required surface treatment effect:
Determine the required type of surface treatment. Smoother surfaces typically require smaller steel shots, while rougher surfaces can be achieved using larger steel shots. For tasks like projectile ejection, it is usually ideal to use uniformly sized steel shots.
Size of steel shot:
Larger steel shots have a greater impact on the surface, making them suitable for removing heavy coatings. Smaller steel shots provide finer processing and are suitable for detailed work on thinner materials.
Types of pollutants to be removed:
For removing heavy rust or scales, larger and harder steel shots may be required.
For mild cleaning or paint removal, medium or smaller steel shots may be effective enough.
Hardness of steel shot:
Harder steel shot is more aggressive and effectively removes sturdy coatings, but it can cause more wear and tear on the equipment. Softer steel shot has lower aggressiveness, is suitable for more detailed processing, and is more gentle on machinery.
Efficient surface cleaning:
Steel shot blasting is very effective in removing rust, oxide scale, and old paint, providing a clean surface for subsequent paint or coating processes.
Compared to manual cleaning methods, it can clean the surface faster and more thoroughly.
Uniform surface finish:
Providing a consistent and uniform surface finish is crucial for coating adhesion and overall appearance.
The spherical characteristics of steel shot ensure uniform coverage and treatment of the entire surface.
Enhanced mechanical performance:
This process can generate compressive stress on the surface, which helps improve fatigue strength and resistance to stress corrosion cracking, especially beneficial for metal shot peening applications.
Minimum dust generation:
Compared to sandblasting or other grinding methods, it produces less dust, improves visibility during operation, and shortens cleaning time.
Shot blasting is a universal and widely used process in various industries due to its effectiveness in surface cleaning, preparation, and precision machining. Here are some key application areas:
Utilized for cleaning and preparing metal components such as chassis, gears, and panels before painting. Highly effective for removing rust, oxidation, and old paint from car parts during restoration or repair processes.
Shipbuilding and Marine Industry:
Essential for cleaning and preparing ship hulls, decks, and other maritime components before painting and coating applications. Helps in removing barnacles and rust, providing a clean surface for ongoing maintenance and repair work.
Employed in surface treatment of aircraft parts to ensure optimal paint adhesion and enhance fatigue resistance through shot blasting techniques.
Construction and Infrastructure:
Used for cleaning and preparing structural steel in bridges, buildings, and other infrastructural projects before coating or painting. Beneficial in concrete preparation for texturing surfaces, improving the bonding of new concrete or coatings.
In foundries for the cleaning of castings, removing sand and scales. Plays a pivotal role in surface preparation in metal manufacturing processes, especially before welding or painting.
Integral in the cleaning and maintenance of locomotives and railway components. Prepares surfaces for painting and coating as part of refurbishment and manufacturing procedures.
Yafeite Group is the leading manufacturer of metal abrasives including steel shot, steel grit, stainless steel shot, and steel cut wire shot. We have introduced advanced testing equipment (Ervin fatigue tester) from USA Ervin Company and can test the technical indexes, mechanical properties, and the fatigue life of metallic abrasives.
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