DUPLEX STAINLESS STEEL PIPE FITTINGS FEATURES
Duplex stainless steel pipe and fittings has good welding performance,
compared with the ferritic stainless steel and austenitic stainless steel,
it is neither like ferritic stainless steel weld heat affected zone,
as grain coarsening and make the plastic toughness sharply lower,
also don’t like austenitic stainless steel, the welding thermal crack is more sensitive.
Duplex stainless steel pipe and fittings because of its special advantages,
is widely used in petroleum chemical industry equipment, water and waste water treatment equipment,
oil gas transmission pipeline, paper making machinery and other industrial areas,
has also been used for bridge bearing structure field in recent years, has the very good development prospect.
The duplex stainless steel pipe and fittings is half of the ferritic and austenitic elements in its solid quenched tissue,
and the normal minimum phase of the phase may be up to 30%
Compared with austenitic stainless steel, the advantages of duplex stainless steel pipe and fittings
(1) the yield strength is more than twice as high as the average austenitic stainless steel, and it has the flexibility to be molded. It is helpful to
reduce the cost by using a dual-phase stainless steel tank or pressure vessel with a thickness of 30 to 50% less than the usual austenitic body.
(2) has excellent resistance to stress corrosion cracking ability, even the lowest of duplex stainless steel alloy content than austenitic stainless
steel has a higher resistance to stress corrosion cracking ability, especially in the environment of the chlorine ion.
Stress corrosion is an outstanding problem that ordinary austenitic stainless steel is difficult to solve.
(3) the most widely used in many medium of 2205 duplex stainless steel corrosion resistance is superior to the ordinary 316 l austenitic stainless steel,
and super duplex stainless steel has high corrosion resistance, and then some medium,
such as acetic acid, formic acid and even can take the place of austenitic stainless steel, high alloy and corrosion resistant alloy.
(4) has a good resistance to local corrosion performance, compared to the alloy content quite austenitic stainless steel,
its wear resistance corrosion and corrosion fatigue performance is better than that of austenitic stainless steel.
(5) lower than the linear expansion coefficient of austenitic stainless steel and carbon steel, suitable for connecting with carbon steel,
has important engineering significance, such as production of composite panels or lining, etc.
(6) no matter under the condition of dynamic load and static load, than austenitic stainless steel has higher energy absorption capacity,
the structure to cope with sudden accidents such as collision, explosion, etc., obvious advantages, duplex stainless steel has practical application value.
Compared with austenitic stainless steel, the disadvantages of duplex stainless steel pipe and fittings
(1) application of universality and multifaceted than austenitic stainless steel, such as its temperature must be controlled under 250 ℃.
(2) its malleable toughness is lower than austenitic stainless steel, cold, hot processing technology and forming performance are not as good as austenitic stainless steel.
(3) the existence of a medium temperature embrittlement zone requires strict control of the process system of heat treatment and welding
to avoid the occurrence of harmful phases and damage performance.
DUPLEX STAINLESS STEEL PIPE AND FITTINGS SUPPLIERS,MANUFACTURERS,STOCKHOLDER IN CHINA
Compared with ferritic stainless steel, the advantages of duplex stainless steel pipe and fittings
(1) comprehensive mechanical properties are better than ferritic stainless steel, especially plastic toughness, which is not sensitive to brittleness as ferritic stainless steel.
In addition to the corrosion resistance, other resistance to local corrosion is better than that of ferritic stainless steel.
The performance of cold processing and cold forming are better than that of ferrite stainless steel.
(4) the welding performance is also far superior to that of ferrite stainless steel, which is not preheated before welding, and no heat treatment is required after welding.
(5) the scope of application is wider than that of ferrite stainless steel.
Compared with ferritic stainless steel, the disadvantages of double phase stainless steel
The alloy element is high, the price is relatively high, ordinary ferrite has no nickel.