Study on Microstructure and Property of High Boron Alloyed Stainless Steel Composite Plate Containing Titanium

A certain amount of Ti was added into high boron alloyed stainless steel with content 2.25%B, and then high boron alloyed stainless steel composite casting slab with three layers was fabricated , in which central layer is high boron alloyed stainless steel containing Ti and cladding is plain 304 stainless steel without Ti. The microstructure of core and interface and the mechanical property of the composite plate were studied after hot forged, hot rolled and solution treated process respectively. The results show that the boride in as-cast microstructure of core are (Fe,Cr)2B phase with long strip and TiB2 phase with petal shape, moreover the formation of TiB2 phase decreases the amount of (Fe,Cr)2B phase. Two kinds of boride are fully broken after hot rolling and distributed in the form of block uniformly in matrix, and TiB2 phase is more fine uniform. The mechanical property especially plastic performance of high boron alloyed stainless steel composite plate containing Ti after solution treatment is improved significantly, it has reached and surpassed the United States ASTM A887-89 delivery standards.