What are Duplex grades 1.4462, 1.4410, 1.4501 AND 1.4507?
What are Duplex grades 1.4462, 1.4410, 1.4501 AND 1.4507?13th January 2021
DIN EN 1.4462, 1.4410, 1.4501 and 1.4507 are duplex and super duplex stainless steel designations used across multiple DIN, EN and ISO standards.
DIN stands for Deutsches Institut für Normung e.V., and it is the German national organisation for the creation and maintenance of around thirty thousand DIN Standards, covering nearly every field of technology. Most of the relevant DIN standards are incorporated in to Euronorm (EN) standards for adoption beyond just Germany.
The Different Grades of Duplex Stainless Steels
DIN EN 1.4462 equates to UNS S31803 (ASTM A182 F51) and UNS S32205 (ASTM A182 F60). The former caption was the original one for a 22% Cr duplex stainless steel. However, as explained in an earlier article, manufacturers optimised the composition towards the top end of the limits to improve pitting corrosion resistance. This grade, with a tighter specification, is captioned as UNS S32205. Consequently, S32205 can be dual-certified as S31803 but not vice-versa. It accounts for around 80% of overall duplex stainless steel production. Langley Alloys stock of DIN EN 1.4462 includes Sanmac 2205, which is Sandvik’s proprietary product that provides ‘enhanced machinability as standard’. Our stock range goes from ½” up to 450mm diameter solid bars, plus hollow bars and plate too.
DIN EN 1.4410 equates to UNS S32750 (ASTM A182 F53). This is the 25% Cr super duplex stainless steel most widely promoted by Sandvik as SAF2507. With an increased chromium content compared with 1.4462 it offers improved pitting corrosion resistance. The yield strength is also higher, allowing component designers to reduce section size for load-bearing applications. Langley Alloys stocks SAF2507 solid bars from Sandvik, in sizes from ½” to 16” diameter.
DIN EN 1.4501 equates to UNS S32760 (ASTM A182 F55). The origins of this grade can be traced back to the development of Zeron 100 by Platt & Mather, Manchester UK. It is another super duplex stainless steel based upon a 25% Cr composition, but with an addition of tungsten. Langley Alloys stocks SAF32760 solid bars from Sandvik, in sizes from ½” to 16” diameter.
DIN EN 1.4507 equates to UNS S32550 (ASTM A182 F61). This, in turn, approximates to Ferralium 255, the original super duplex stainless steel invented by Langley Alloys. Launched in 1969, it has now provided more than 50 years successful service in a wide range of demanding applications. Compared with F53 and F55 it delivers increased strength and corrosion performance. Its minimum yield strength exceeds 85ksi, whereas other grades are limited to 80ksi. In addition, it contains up to 2.0% of copper, which aids pitting corrosion resistance. Langley Alloys stocks Ferralium 255-SD50 in sizes from 5/8” to 14” diameter solid bar, plus plates up to 3” thickness.
A number of other duplex stainless steels exist, such as lean duplex DIN EN 1.4362 (F68, UNS S32304) and hyper duplex DIN EN 1.4658 (UNS S32707). However, these products are mostly supplied as tubes and not readily available from stock.
Langley Alloys offers the most comprehensive range of duplex and super duplex stainless steels, operating from locations in the UK and USA (Portland, Houston).
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