What is shot peening ?

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Shot peening
What is shot peening ?

What is shot peening – ultrasonic shot peening ?

Our shot peening process is used to improve:

Fatigue resistance
Resistance to stress corrosion cracking and contact fatigue

This surface impact treatment solution consists in bombarding the specific area to be peened with small projectiles (= media). This action induces residual compressive stress on the surface, which delays the appearance of cracks, and improves the lifetime of the part. This is a cold working and work hardening process.

Download our dedicated brochure on portative Ultrasonic Shot Peening

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Browse the tabs below to explore in detail principle, methods, advantage and certification of shot peening.

PRINCIPLE
METHODS
ADVANTAGES
CERTIFICATION

PRINCIPLE

Principle of shot peening, work hardening and cold working process.

J.Almen discovered shot peening in the 1930s while working for General Motors.

Shot peening is a process used to induce superficial compressive stress, and to modify the mechanical properties of metals. The method consists in striking a surface with projectiles (metal, glass or ceramic beads) at high speed, with sufficient force to create a plastic deformation: each ball acts like a mini-hammer.

Objective of shot peening

Shot peening, due to the successive impacts, causes changes in the mechanical properties of the surface. Shot peening is often required for repairs to fragile areas, to compensate for tensile stresses due to machining and to replace them with compressive stresses.

Shot peening can improve fatigue resistance from 0 to 1000%. But this depends of:

the part geometry and material
the projectile material,
the projectile quality,
the projectile intensity
it field of action

The compressive surface stresses create fatigue resistance and resistance to certain forms of stress corrosion cracking., mains advantages or this work hardening and cold working process.

Scientific press reviews

METHODS

Conventional methods of shot peening propel projectiles using compressed air and centrifugal wheel systems. Other methods include ultrasonic shot peening, wet shot peening and laser peening (which does not use projectiles).

SONATS specialises in ultrasonic shot peening, STRESSONIC® technology has matured and has proven its advantages.

ADVANTAGES

Advantages of shot peening

SONATS provides innovative ultrasonic shot peening equipment. The equipment is developed using STRESSONIC® technology and offers new solutions to overcome the limits of conventional shot peening. This means:

Increased productivity and quality

improved fatigue resistance
processing of complex geometry parts
low roughness

Lower costs

shorter treatment cycle
reduction in the amount of medias, energy and compressed air used
easy integration into the production line
treatment often possible in-situ without dismantling equipment to isolate the work piece

Moreover, the use of high quality beads and real-time parameters control ensure repeatability and treatment efficiency.

Ultrasonic shot peening generates an optimal surface condition (roughness) and is generally better than conventional shot peening processes.

Comparison of surface condition (roughness and shot peening post-treatment) on two 7000 series aluminium strips with identical shot peening intensity (12A)

TECHNICAL AND SCIENTIFIC PUBLICATION

Consult publications about ultrasonic shot peening process (simulation, improvement of fatigue effects, nanocrystallisation, ceramic shotpeening…)