According to the characteristics of the two-phase structure, by properly controlling the chemical composition and heat treatment process, the excellent toughness and weldability of austenitic stainless steel are combined with the higher strength and chloride stress corrosion resistance of ferritic stainless steel, making duplex stainless Čelik Vrsta čelika koji kombinira izvrsnu otpornost na koroziju, visoku čvrstoću i jednostavnu preradu i proizvodnju. Their physical properties are between austenitic stainless steel and ferritic stainless steel, but closer to ferritic stainless steel and carbon steel. The resistance to chloride pitting and crevice corrosion of duplex stainless steel is related to the content of chromium, molybdenum and nitrogen. Its resistance to pitting and crevice corrosion can be similar to that of 316 stainless steel, or higher than that of stainless steel for seawater, such as 6%MO austenitic stainless steel. All duplex stainless steels are significantly more resistant to chloride stress corrosion cracking than 300 series austenitic stainless steels, and their strength is also much higher than austenitic stainless steels, while showing good plasticity and toughness.

1. u usporedbi s austenitnim nehrđajućim čelikom

2) Ima izvrsnu otpornost na pucanje korozije stresa, posebno u okruženjima koja sadrže kloridne ione. Čak i dupleksni nehrđajući čelik s najmanjim sadržajem legure ima veću otpornost na pucanje korozije stresa od austenitnog nehrđajućeg čelika. Korozija stresa istaknut je problem koji je teško riješiti obični austenitni nehrđajući čelik. 3) The corrosion resistance of the most common 2205 duplex stainless steel used in many media is better than that of ordinary 316L austenitic stainless steel, and super duplex stainless steel has extremely high corrosion resistance. In some media, such as acetic acid and formic acid, it can even replace high-alloy austenitic stainless steel and even corrosion-resistant alloys. 4) Ima dobar lokalni otpor korozije. Compared with austenitic stainless steel with the same alloy content, its wear corrosion resistance and corrosion fatigue resistance are better than austenitic stainless steel. 5) The linear expansion coefficient is lower than that of austenitic stainless steel, close to that of carbon steel, suitable for connection with carbon steel, and has important engineering significance, such as the production of composite plates or linings.

2. U usporedbi s feritnim nehrđajućim čelikom, prednosti dupleks nehrđajućeg čelika su sljedeće:

5) Raspon primjene je širi od onog feritnog nehrđajućeg čelika.

Prijava

Due to the high strength of duplex steel, it can often save materials, such as reducing the wall thickness of the pipe. Take SAF2205 and SAF2507W as examples. SAF2205 is suitable for use in chlorine-containing environments. Ovaj je materijal pogodan za rafiniranje ulja ili druge procesne medije pomiješane s kloridima. SAF2205 je posebno prikladan za izmjenjivače topline koji koriste vodene otopine koje sadrže klor ili pomalo slanu vodu kao medija za hlađenje. Ovaj je materijal pogodan i za razrijeđene otopine sumporne kiseline i čiste organske kiseline i njihove smjese. For example: oil pipes in the oil and gas industry: crude oil desalination in refineries, sulfur-containing gas purification, wastewater treatment equipment; Sustavi hlađenja koji koriste malo slane vode ili otopine koje sadrže klor.