404GP Stainless Steel – The Ideal Alternative to 304 Stainless Steel – Properties and Benefits of 404GP

Austral Wright Metals - part of the Crane Group of Companies, is the result of the merger of two long established and well respected Australian owned metal distribution companies. Austral Bronze Crane Copper Ltd and Wright and Company Pty Ltd.

This merger has bought together Australia's leaders in the distribution of:

• Aluminium - Coil, sheet, plate, tread plate etc
• Copper, brass, bronze - Sheet, coil, extrusions and tube
• Nickel and High Performance Alloys - Hollow and bar, sheet, plate in alloys such as Incoloy, Inconel and Monel
• Stainless steel - Sheet, coil, plate, flat, angle, round, tube, fittings, consumables
• High Performance Materials including, titanium, duplex alloys, cobalt alloys, copper nickels, welding consumables and other high technology metals

404GP Stainless Steel

Corrosion Resistance of Stainless Steel 404GP

Grade 404GP™ can be used instead of grade 304 stainless steel in most applications. The corrosion resistance of Grade 404GP™ is at least as good as grade 304, usually better: it is not affected by stress corrosion cracking in hot water, and is not subject to sensitisation when welded.

Grade 404GP™ is a new generation ferritic stainless steel made by a premium Japanese mill with state-of-the-art new generation steelmaking technology – with Extra Low Carbon.

Work Hardening 404GP Stainless Steel

Grade 404GP™ can be worked by all the methods used with 304. It work hardens similar to carbon steel, so it doesn’t cause all the hassles familiar to workers with 304.

Magnetic Properties of 404GP Stainless Steel

The very high chromium content – 21% - of Grade 404GP™ makes it much better than the common ferritic grade 430 for corrosion resistance. So don’t worry that Grade 404GP™ is magnetic – so are all the duplex grades, e.g. 2205.

Fabricating with 404GP Compared to 304 Stainless Steel

You can use Grade 404GP™ as a general purpose stainless steel instead of the old workhorse grade 304 in most applications. Grade 404GP™ is easier to cut, fold, bend and weld than 304. This gives a better looking job – cleaner edges and bends, flatter panels, neater construction.

As a ferritic stainless steel, Grade 404GP™ has higher yield strength than 304, similar hardness, and lower tensile strength and tensile elongation. It has much lower work hardening – which is what makes it easier to work with, behaving like carbon steel in fabrication.

Cost Advantages of 404GP Stainless Steel over 304 Stainless Steel

Grade 404GP™ costs up to 20% less than 304. It weighs less, giving 3.5% more square metres per kg. And better workability reduces labour costs, tool costs and maintenance costs.

Availability of 404GP Stainless Steel

Grade 404GP™ is available now from Austral Wright Metals, from stock, as coil & sheet in 0.55, 0.7, 0.9, 1.2, 1.5 and 2.0 mm thickness.

Finishes are No4 and 2B. The 2B finish on Grade 404GP™ is brighter than 304. Do not use 2B where appearance is important – the gloss may vary across the width.

Weldability of 404GP Stainless Steel

Grade 404GP™ is weldable. You can use TIG, MIG, spot and seam welding. See Austral Wright Metals datasheet on “Welding New Generation Ferritic Stainless Steels” for advice.

Properties of 404GP Stainless Steel

Chemical Composition of 404GP Stainless Steel

Typical Chemistry of Grade 404GP™ compared to 304 & 430

Mechanical Properties of 404GP Stainless Steel

Typical Mechanical Properties of Grade 404GP™ compared to 304 & 430

Physical Properties of 404GP Stainless Steel

Typical Physical Properties of Grade 404GP™ compared to 304 & 430

Corrosion Performance

Salt Spray Test

Figure 1. Slat spray test corrosion samples of 430, 304 and 404GP stainless steels after four months in 5% salt spray at 35ºC

Atmospheric Corrosion

Figure 2. Atmospheric corrosion of 430, 304, and 404GP stainless steels after one-year actual exposure next to Tokyo Bay.

Summary

Grade 404GP™ is a new generation ferritic stainless steel grade from the premium Japanese mill JFE Steel Corporation, who brand it 443CT. The grade is new, but the mill has many years of experience with similar high quality grades, and you can be confident it won’t let you down.

Like all ferritic stainless steels, Grade 404GP™ should be used only between 0ºC and 400°C, and should not be used in pressure vessels or structures without full qualification.

This information has been sourced, reviewed and adapted from materials provided by Austral Wright Metals - Ferrous, Non-Ferrous and High Performance Alloys.

For more information on this source, please visit Austral Wright Metals - Ferrous, Non-Ferrous and High Performance Alloys.