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过去35年,已经开发出两大类高强度棒材和锻件用微合金化(MA)钢。第一类是1974年开发的,为中碳钢中加入少量的铌或钒。这些早期的中碳钢为珠光体-铁素体组织,具有高的强度和良好的高周疲劳性能。大约15年之后,微合金化多相钢被开发出来,根据材料加工工艺不同,组织由铁素体、贝氏体、马氏体以及残余奥氏体等组成。这类钢可以达到非常高的强度,同时具有良好的疲劳性能和高的断裂性能。在20世纪70年代早期,高强度锻件仅能通过最终的热处理过程实现,热处理包括加热、淬火及回火(QT)。已经不断地被证实由MA珠光体-铁素体钢生产的空冷锻件可以实现与更昂贵的热处理锻件类似的强度和疲劳性能。介绍过去35年来微合金化珠光体-铁素体钢的发展。
For the past 35 years, two broad categories of high-strength bar and microalloyed (MA) steels for forgings have been developed. The first category was developed in 1974 to add a small amount of niobium or vanadium to medium-carbon steels. These early carbon steels are pearlite-ferrite structures with high strength and good high-cycle fatigue properties. About 15 years later, microalloyed multiphase steels were developed. Depending on the material processing technology, the microstructure consists of ferrite, bainite, martensite, and retained austenite. This type of steel achieves very high strength with good fatigue properties and high fracture properties. In the early 1970s, high-strength forgings were only available through the final heat treatment, which included heating, quenching and tempering (QT). It has been continuously confirmed that air-cooled forgings produced from MA pearlite-ferritic steels achieve similar strength and fatigue properties as more expensive heat-treated forgings. Introduction to the development of microalloyed pearlite-ferritic steels over the past 35 years.