Product introductionWhat is duplex stainless steel pipe?
Duplex stainless steel pipe welding performance, compared with ferritic stainless steel and austenitic stainless steel, it is neither like ferritic stainless steel welding heat-affected zone, due to severe coarsening of the grain, plasticity toughness significantly reduced, nor like ferritic stainless steel welding heat-affected zone. Austenitic stainless steel, more sensitive to weld heat cracking.
Duplex stainless steel due to its special advantages, widely used in petrochemical equipment, seawater and wastewater treatment equipment, oil and gas pipelines, paper making machinery and other industrial fields, in recent years has also been studied for the bridge bearing structure field, with good prospects for development.
Duplex stainless steel is in its solid hardening organization in the ferrite phase and austenite phase each half, the general minimum phase content of perhaps 30%.
Folding and austenitic stainless steel compared to the advantages of duplex stainless steel
(1) yield strength than ordinary austenitic stainless steel is more than twice as high, and has sufficient plastic toughness required for molding. The use of duplex stainless steel manufacturing tanks or pressure vessels to reduce the wall thickness of 30-50% than the commonly used austenitic, which helps to reduce costs.
(2) has excellent resistance to stress corrosion rupture, even the lowest alloyed duplex stainless steel also has a higher resistance to stress corrosion rupture than austenitic stainless steel, especially in the environment containing chloride ions. Stress corrosion is a prominent problem that is difficult to solve with ordinary austenitic stainless steel.
(3) In many media the most common application of 2205 duplex stainless steel corrosion resistance than ordinary 316L austenitic stainless steel, and super duplex stainless steel has very high corrosion resistance, and then some media, such as acetic acid, formic acid, etc. can even replace the high alloy austenitic stainless steel, and even corrosion-resistant alloys.
(4) has good local corrosion resistance, compared with austenitic stainless steel with comparable alloy content, it is better than austenitic stainless steel in terms of wear corrosion and fatigue corrosion resistance.
(5) lower coefficient of linear expansion than austenitic stainless steel, and carbon steel is close, suitable for connection with carbon steel, has important engineering significance, such as the production of composite plates or lining.
(6) Whether in dynamic or static load conditions, than austenitic stainless steel has a higher energy absorption capacity, which is the structural components to cope with sudden accidents such as ramming, explosion, etc., duplex stainless steel advantages are obvious, there are practical applications.
Chemical composition of 304 stainless steel pipe: