Bimetallic screw & barrel

▌Brief Introduction:

Bimetallic screws are using 38CrMoAlA as basic material, high quality bimetallic alloy powders as another metal material, do machine or manual spray welding for different sizes and structures screws to let bimetallic powders combine with basic materials, finally reach the result that screws are much wear-resisting to reach 2-3 times lifespan than normal 38CrMoAlA nitriding screws. 

Bimetallic barrels have two types:

One type is the same like bimetallic screws, make 4-8 straight grooves on one barrel inner wall, do spray welding to let bimetallic powder fill in the grooves.

Second one type is put bimetallic alloy powders inside barrel, do centrifugal casting, to make barrel inner wall whole bimetallic powders coating.

The bimetallic technics are not necessary, it depends on customers’ requiements and budguts.

▌Basic material: 38CrMoAlA (JIS SACM645)

▌Bimetallic powders: Nickel-based alloy+tungsten carbide

(If you request special bimetallic powders, please indicate with our sales engineers)

▌Basic Technics:

Tempering treatment

Nitriding treatment

▌Bimetallic Technics:

Bimetallic welding / Bimetallic centrifugal casting

▌Technical Parameter:

Hardness after tempering: HB260-320
Nitriding hardness: 900-1050HV
Nitrided layer depth: 0.5-0.8mm
Nitrided brittleness: Less than grade 2
Surface roughness: Ra0.4
Screw straightness: 0.015mm

Double bimetallic layer depth: 3mm

Bimetallic layer hardness: HRC58-62