NITRONIC 30 Stainless Steel - UNS S20400

NITRONIC 30 is a nitrogen-strengthened stainless steel developed for applications requiring a good level of aqueous corrosion resistance combined with good toughness and economy.

NITRONIC 30 Stainless Steel provides approximately 50% higher yield strength than Type 304L and, therefore, may allow lighter gages to further reduce costs.

NITRONIC 30 Stainless Steel work hardens rapidly while retaining good ductility. Unlike other nitrogen-strengthened stainless steels, NITRONIC 30 Stainless Steel is subject to magnetic transformation when cold worked.

We provide you with a variety of NITRONIC 30 product forms, including but not limited to:

NITRONIC 30 Stainless Steel is listed as Grade UNS S20400 in ASTM A240-Plate, Sheet and Strip for Pressure Vessels.

ASTM A666 - Austenitic Stainless Steel Sheet, Strip, Plate and Flat Bar.

NITRONIC 30 Stainless Steel offers significantly higher strength than Type 304 and potential for applications requiring good resistance to aqueous and atmospheric corrosion resistance combined with good toughness and economy. Specific potential applications include automotive hose clamps, safety belt anchors, truck and bus frames, water supply and control structures, sewage treatment plant structures, bulk solids handling equipment, magnetic ore separator screens, coal buckets and hopper cars.

 

Stainless steels have served successfully in many structural components in the transportation industry. Bus space frames and bumpers take advantage of the excellent fabricability and high strength and toughness of stainless. NITRONIC 30 Stainless Steel has been used in rapid transit structurals where the strength-to-weight ratio of up to three times that of carbon steel has improved operating efficiency. Rear frames of refrigerated trucks are easily welded and formed from NITRONIC 30 Stainless Steel, resulting in protective units that can withstand impact blows without cracking. Shipboard container structurals use stainless steel successfully because carbon steel becomes scuffed and rusts wherever the paint is damaged.

The outstanding corrosive wear resistance of NITRONIC 30 under many different sliding conditions. The stainless steels as a class are much more abrasion resistant than abrasion resistant (AR) steels under even mildly corrosive conditions. NITRONIC 30 is more cost effective than Types 409 and 304 which are typically used in wet abrasive applications.

NITRONIC 30 Stainless Steel exhibits good corrosion resistance to a variety of media. Pitting resistance, as measured by tests in 10% FeCl3 solution, is better than Type 304. In sulfuric acid and hydrochloric acid, NITRONIC 30 is much better than Types 409 and 410 and approaches Type 304 in more dilute solutions.

Intergranular attack tests were performed following the procedures of ASTM A262 on duplicate annealed sheet specimens of NITRONIC 30 and Type 304 stainless steels. Before testing, some of these specimens were heat treated at 1250 F (675 C) for one hour and air cooled to exaggerate the conditions that might be found in the heat-affected zones of heavy weldments.

The threshold stress for cracking of NITRONIC 30 stainless in boiling 42% MgCl2 solution (a very severe test) is about 25 ksi (172 MPa), compared with about 10 ksi (69 MPa) for Types 304 and 304L. This means that NITRONIC 30 is markedly more resistant than these alloys to cracking in hot chloride solutions at lower stress levels. At higher stress levels (about 25 ksi and above) the chloride stress-corrosion cracking resistance of NITRONIC 30 is about like that of Types 304 and 304L.

Early experience with NITRONIC 30 stainless shows good welding characteristics. It can be fusion welded with the usual arc welding processes employed for austenitic stainless steels. Armco NITRONIC 30 provides superior ductility and toughness, as well as resistance to weld cracking without the need for preheating or postheating, as most martensitic and heavy-gage ferritic stainless steels require.

A small quantity of ferrite will form in autogenous NITRONIC 30 stainless welds to minimize any hot cracking sensitivity. Arc welding parameters more closely approximate those of the other NITRONIC grades (e.g., slower weld travel, hotter shielding gas for GTAW - Ar + 5% H2 or He), rather than the standard austenitic stainless steels. Standard AWS austenitic stainless fillers or the newly included AWS A5.9 and A5.4 NITRONIC fillers (209, 240, 219) can be selected for any particular application.