MACHINING & TREATMENTS
PRODUCTS
AB&S-AVVITO S.r.l. proposes:
HYDROGEN SERVICE
Screws in nickel and austenitic stainless steel alloys for oil & gas, extraction and refinery plants
Screws in nickel and austenitic stainless steel alloys for oil & gas, extraction and refinery plants
When hydrogen takes form of H2S (hydrogen sulphide), HCN (hydrogen cyanide), in stream or in the presence of syngas (mixture of hydrogen, methane, carbon dioxide, carbon monoxide), high risks may arise for used materials, in our case are screws:
- stress states may enhance, leading to breakage of the screws;
- it can be absorbed by the materials and create delayed cracking
In order to avoid such problems, it is advisable to use materials such as Nickel alloys, Hastelloy C276, Inconel 625, Inconel 600.
These materials have excellent characteristics, but with a HIGH COST.
Using stainless steel AISI 316, AB&S-AVVITO has developed a specific heat treatment stress relieving (AB&S treatment), that makes screws softer in the entire section and, at the same time, prevents the formation of sigma phase and precipitation-carbide within the structure of the fasteners.
Currently the treatment is applicable on small-medium sized cold forged screws.
This process that has been approved with a series of specific tests and has been confirmed with consolidated supplies, has the advantage of a SIGNIFICANT REDUCTION IN COSTS OF THE SCREWS .
The choice of suitable material is, however, up to the Customer, based on the service conditions of the system.
Don’t hesitate to contact us for any further information you may need.
