The production process of cast steel metal shot, of spherical and grits type, foresees casting of selected scrap and choiced alloys.
The cast material is poured and at the same time stroked by a high-pressure water jet. Small particles are formed this way. They fall down into a water tank beneath and get solid in spherical grains.
Once bad formed grains are eliminated through riddling, the spherical shot is subdivided according to the dimension and subsequently thermally treated.
This process is followed by a final phase, which foresees three different types of checks:
- micro-structural check;
- hardness check;
- further dimensional check.
The grits is obtained by crumbling the spherical shot and bad formed grains, sifting it according to the dimension and treating it to obtain the desired hardness.
The shots obtained in this way remarkably vary in shape and dimension, and versatilely adapt themselves to various uses.
For particular applications TECHMA has created spherical/spherical, spherical/sharp, sharp/sharp mixes according to the final use of the product itself.
Uses and Advantages
Owing to technical reasons the same shots are not suitable to be used on suction pressure compressed-air cabins for sandblasting.
Spherical shots are also used in the processes of shot peening / peen forming.
Due to the fact that the cost of scrap surcharge is variable, since the 1980s, the producers decided to separate it from the price of the cast steel shot and grit and link it to market indices.
The cost of the cast steel shot and grit is therefore the sum of two components: a base price + the scrap surcherge of the reference month.