Development of TRIP-aided Steels for Diesel Engine Common Rail Enduring Ultra High Pressure

为适应柴油机共轨在3000bar超高压下的应用，研制了0.2-0.4%C-1.5%Si-1.5%Mn-0.05%Nb-Cr-Mo-Ni-B TRIP助力贝氏体铁素体钢(TBF钢)和TRIP助力马氏体钢(TM钢)。此外，为了获得高的强韧性组合和高的缺口疲劳强度，提出了以下几点建议：(1)TBF和TM钢的最佳化学成分；(2)热锻超细晶化和随后的等温或等温转变保温；(3)贝氏体铁素体和马氏体的最佳比例(BF/M)和富碳机制。

For application to diesel engine common rail enduring ultra high-pressure of 3000 bar, 0.2-0.4%C-1.5%Si-1.5%Mn-0.05%Nb-Cr-Mo-Ni-B TRIP-aided bainitic ferrite steels (TBF steels) and TRIP-aided martensitic steels (TM steels) were developed. In addition, the followings were proposed to achieve high combination of strength and toughness and high notch-fatigue strength.(1) optimum chemical composition for the TBF and TM steels.(2) ultra-fine graining by hot-forging and consequent austempering or isothermal transformationholding(3) optimum ratio (BF/M) of bainitic ferrite and martensite and carbon-enrichment mechanism