Super cruach dhosmálta déphléacsachaneart agus friotaíocht creimeadh i bhfad níos airde a sholáthar ná 316. Dá bhrí sin, is ea an freagra láithreach - is fearr déphléacsacha super316.
'Duplex' stainless steels are a family of stainless steels that contain a mixed microstructure of austenite and ferrite phases. They offer a combination of good corrosion resistance and high strength, making them suitable for a wide range of applications. Super duplex stainless steels have a higher content of alloying elements, such as chromium, nickel, and molybdenum, compared to duplex stainless steels. They are based upon 25% chromium content. As such, super duplex stainless steels have up to four times the tensile strength of 316 stainless steel, and considerably better corrosion resistance. An alloys resistance to pitting corrosion can be usefully summarised by the PREN value, which is the 'Pitting Resistance Equivalent number'. The PREN for super duplex stainless steels is >40, i gcomparáid leis an PREN do 316 de 25.
Mar sin féin, in ainneoin na buntáistí an-tarraingteach a bhaineann le steels dhosmálta super déphléacsacha os cionn 316, tá roinnt teorainneacha ann. Cailleann cruacha dhosmálta sárdhéphléacsacha cuid mhór dá déine tionchair faoi -50degC, ach i gcás 316 coinnítear an déineacht tionchair den chuid is mó mar gheall ar theocht chrióigineach. Tá steels dhosmálta Super déphléacsacha teoranta do theocht oibriúcháin fadtéarmach faoi bhun 250degC, ach is féidir 316 a úsáid suas le 870degC (chomh fada agus is ísealcharbóin é316Lnó tíotáiniam chobhsaithe 316Ti leagan chun creimeadh intergranular a sheachaint).
Is cinnte go bhfuil cruach dhosmálta sárdhéphléacsacha níos deacra le meaisíniú, mar gheall ar a neart i bhfad níos airde. Feictear go bhfuil siad níos deacra a tháthú ach is féidir iad a dhéanamh go héasca leis an trealamh agus na nósanna imeachta cuí.
