Shot Peening

Description

Shot peening is a technology that was discovered by serendipity, i.e., unintentionally. In the 1930s, it was observed that car engine valve springs, when cleaned by sandblasting, had a longer service life. These springs are submitted to a high level of stress and so tend to break due to metal fatigue. Consequently, the engineers of that era became interested in these new findings and developed the shot-peening process.

Shot peening consists in striking a surface with shot media to improve certain mechanical features and to increase part service life. This process consists in producing a residual stress on the surface of the workpiece by material compression. One of its advantages is that the induced changes only concern the outer layer of the part and that the core of the material keeps its properties.

In the aeronautics industry, the improvement of surface mechanical characteristics, and particularly resistance to mechanical fatigue, has led to reassess part design and has made it possible to decrease part weight.

Our equipment :

TMH-novatec has been providing shot peening services for now more than 15 years and owns two numerically controlled shot peening machines. One is dedicated to ceramic bead shot peening (AZB425) and the other to cast steel bead shot peening (BA315N / S110).

The shot peened parts are turbine and compressor blades, flowpaths and fan disks for the aeronautics industry.

Capacity of the two machines :

Maximum recommended part height : 600mm
Maximum recommended part diameter : 1200mm
Maximum recommended part weight : 250 kilos

Shot peening is a special process and so the manufacturing parameters that are determined during the development phase are systematically monitored and checked before each production cycle. TMH-novatec is equipped with devices to control the quality and granulometry of the shot peening media. Before each cycle, Almen strip tests are used to check that constraints generated by shot peening and shot peening intensity match the expected constraints.

Our shot peening services can be completed by other processes:

Non-destructive inspection (FPI)
Degreasing
Chemical cleaning to remove steel bead residues

Our qualifications

TMH-novatec has been qualified according to the following specifications :

NADCAP
Pr-3000 for Safran
PAQ58C471 for Safran Power Units
DMP28 for Safran Aircraft Engines

In addition to civil and military aeronautics, our shot peening machines are compatible with part inspection for the nuclear, space, automotive, and energy industries, and for any other industrial purposes.

The applicable international standards are AMS 2430, AMS 2431, AMS 2431/7 et SAE J442, SAE J2597.