How is the impact and friction resistance of reinforced steel shot assessed?

The impact and friction resistance of shot peening steel is an important indicator for assessing its quality and service life. These properties directly affect the effectiveness and efficiency of steel shot in surface treatment processes such as blasting and shot peening. The following is a detailed discussion of the assessment of impact resistance and friction resistance of shot peening steel shot:

I. Impact Resistance Assessment

Impact resistance refers to the ability of a shot to maintain its shape and integrity without breaking when subjected to an external impact. This property is usually assessed by the following methods:

1. Impact test:
   

• Principle: A certain mass of impact hammer is used to impact the steel shot, and the breakage of the shot is observed and recorded.
  

• Procedure: A quantity of reinforced steel shot is placed in a test device, impacted several times using a standard impact hammer, and then the number of shot broken is counted.
  

• Analysis of results: The impact resistance of the steel shot is evaluated according to the percentage of broken steel shot. The lower the percentage of broken pellets, the better the impact resistance of the pellets.
  

2. Falling ball test:
   

• Principle: Evaluate the impact resistance of steel shot by simulating the free-fall impact of the shot during use.
  

• Operation procedure: The steel shot is dropped freely from a certain height and impacted on a hard plane, and the deformation and crushing of the steel shot are observed and recorded.
  

• Analysis of results: Evaluate the impact resistance of the steel pellets according to their deformation and crushing rate.
  

Assessment of Friction Resistance

Friction resistance refers to the ability of a reinforced steel shot to resist abrasion and maintain its shape and properties when in contact with the surface of another object and in relative motion. This property is usually assessed by the following methods:

1. Friction wear test:
   

• Principle: A friction and wear test is carried out on steel shot using a friction and wear tester to simulate the friction conditions during actual use.
  

• Procedure: A reinforced steel shot is placed on the specimen table of the friction and abrasion tester and moves relative to the friction partner, recording the coefficient of friction, the amount of wear and the wear pattern during the friction process.
  

• Analysis of results: The friction resistance of the steel shot is evaluated based on the coefficient of friction, the amount of wear and the wear pattern. The smaller the amount of wear and the more stable the friction coefficient, the better the friction resistance of the steel shot.
  

2. Practical use test:
   

• Principle: The peened steel shot is tested in use under actual working conditions to observe and record its wear and service life.
  

• Operation steps: Apply the steel shot to specific blasting and shot peening processes, and record the quality change, shape change and service life before and after use.
  

• Analysis of results: The friction resistance of steel shot was assessed based on its mass loss rate, shape retention ability and service life.
  

In summary, the assessment of impact resistance and friction resistance of reinforced steel shot requires comprehensive consideration of a variety of factors and methods. Through scientific experiments and testing methods, the performance and quality of steel shot can be accurately assessed, providing a strong basis for the selection of suitable steel shot.