双相沉淀硬化粉冶不锈钢的开发

Development of a dual-phase precipitation-hardening PM stainless steel

不锈钢可通过压制与烧结水雾化粉末来制取。粉冶品级的不锈钢有铁素体、奥氏体、马氏体、两相(铁素体+奥氏体)、双相(铁素体+马氏体)以及沉淀硬化(马氏体)等不锈钢。开发双相粉冶不锈钢反映了对较高强度、较高延性与韧性的需求在增长。在本研究中,开发出一种新的低成本粉冶不锈钢,它将双相(铁素体+马氏体)显微结构与沉淀硬化的优点结合在一起。它与其他沉淀硬化合金不同,尽管这种不锈钢在时效后强度与韧性有所提高,但延性与冲击韧度的提高更大。借助组成与显微结构评估了新合金的力学性能。

Stainless steels can now be fabricated by the pressing and sintering of water atomized powder. PM grades embrace： ferritic, austenitic, martensitic, duplex （ ferritic ＋ austenitic ）, dual-phase （ ferritic ＋ martensitic ） , and precipitation hardening （ martensitic）. Development of dual-phase PM stainless steels reflects the growing need for higher strength,coupled with ductility and toughness. In the present study, a new low-cost PM stainless steel has been developed which combines the advantages of a dual-phase （ ferrite ＋ martensite） microstructure with precipitation hardening. Unlike other precipitation hardening alloys, ductility and impact toughness increase significantly upon aging, notwithstanding attendant increases in hardness and strength. The mechanical properties of the new alloy are evaluated in terms of composition and microstructure.