Views: 4 Author: Site Editor Publish Time: 2019-08-01 Origin: Site
Bellows Material---Nickel Alloys
We generally use bellows of material stainless steel SS304,SS316L,SS321, in addition , we also use the material of nickel and alloys. This material has different composition structure and content compare to stainless steel,and they're have more higher temperature resistant used in bellows expansion joint.There're more series as these :
Nickel 200(ASTM B162-200)
A commercially pure nickel(99.5% Ni),nickel 200 has good mechanical properties and excellent corrosion resistance to salt water attack and chloride cracking.
Alloy 400 (ASTM B127-400)
This copper-nickel alloy(66.5% Ni,31.5 Cu) is a higher strength material than Nickel 200 with excellent corrosion resistance over a wider range of temperatures and operating conditions.
Alloy 600 (ASTM B168-600)
This nickel-chromium alloy(76% Ni,15.5% Cr) has very desirable properties for the manufacture of expansion joints.It has a very high strength over a wide range of temperatures and a good resistance to a variety of corrosive environments.It finds wide use in steam and salt water services where it is vertually immune to chloride stress corrosion.
Alloy 625 Gr.1(ASTM B443-625)
This alloy contains a higher chromium content(21.5%) than alloy 600. With the addition of 9% molybdenum,it produces an alloy of superior strength and corrosion resistance over a wider range of temperatures and environments.It is used on many critical applications such as heat exchangers and catalytic cracker expansion joints.When exposed to temperatures above 1000 deg F for prolonged periods,it may become embrittled.
Alloy 625 LCF(ASTM B443-625 LCF)
Similar to straight grade 625,this alloy has a slight change in material composition to enhance low-cyclic fatigue properties at elevated temperatures.
Alloy 800(ASTM B409-800)
This nickel-iron-chrome alloy is less expensive than alloy 600.It has good corrosion resistance properties and high temperature strenght over a wide variety of difficult service conditions.
Alloy 825(ASTM B424-825)
This is a copper-chrome nickel alloy that exhibits excellent corrosion resistance to the most severe acids,in particular hot concentrated sulfuric acid and sulfur bearing environments.
Alloy 20 or 20Cb-3(ASTM B463)
This nickel-iron-chrome alloy was specifically designed to resist hot fulfuric acid.It is able to resist intergranular corrosion in the aswelded condition and is practicaly immune to chloride stress corrosion cracking.
Clients can choose any nickel alloy which suit their requirement ,or our technician can also design after clients tell us the detail using environment.