▁designs . ▁ ▁Lower - cost ▁st ain less ▁steel ▁c ath ode ▁pl ates ▁ ▁From ▁ 2 0 0 1 ▁to ▁ 2 0 0 7 , ▁nick el ▁prices ▁rose ▁from ▁an ▁average ▁of ▁US $ 5 9 4 5 ▁to ▁US $ 3 7 , 2 1 6 . ▁Nick el ▁is ▁a ▁key ▁constitu ent ▁of ▁ 3 1 6 L ▁st ain less ▁steel . ▁This , ▁combined ▁with ▁increases ▁in ▁some ▁of ▁the ▁other ▁constitu ents ▁of ▁the ▁ 3 1 6 L ▁al loy , ▁prompt ed ▁X str ata ▁Technology ▁( by ▁then ▁the ▁market ing ▁organisation ▁for ▁the ▁Isa ▁Process ▁technology ) ▁to ▁seek ▁an ▁alternative ▁material ▁for ▁the ▁c ath ode ▁pl ates . ▁ ▁X str ata ▁Technology ▁personnel ▁investig ated ▁the ▁use ▁of ▁a ▁new ▁low - al loy ed ▁du plex ▁st ain less ▁steel , ▁L D X ▁ 2 1 0 1 ▁and ▁ 3 0 4 L ▁st ain less ▁steel . ▁The ▁L D X ▁ 2 1 0 1 ▁contains ▁ 1 . 5 % ▁nick el ▁compared ▁to ▁ 1 0 – 1 4 % ▁in ▁ 3 1 6 L ▁st ain less ▁steel . ▁ ▁L D X ▁ 2 1 0 1 ▁has ▁superior ▁mechanical ▁strength ▁to ▁the ▁ 3 1 6 L ▁st ain less ▁steel , ▁allowing ▁th inner ▁sheets ▁to ▁be ▁used ▁for ▁the ▁c ath ode ▁pl ates . ▁However , ▁the ▁flat ness ▁toler ance