Alloy 321 Stainless steel plate can't be hardened by heat treatment, only by cold working. It could be easily welded and processed by normal shop fabrication practices. For every property remaining when compared, the highest bar is AISI 304H stainless steel and The underside bar is AISI 321H stainless steel. https://madanijayateknik.com/service/detail/round-bar-plate-sheet-pipe-tube-stainless-steel-321-uns-s32100-din-x6crniti18-10-aisi-321-dan-321h-uns-s32109-din-x8crniti18-10-aisi-321h