The influence of Cr and Ni additions and quench and partition (Q&P) processing parameters on the microstructural development, including carbide formation and austenite retention during Q&P, was studied in two steels with a base composition of 0.2C–1.5Mn-1.3Si wt.% and additions of 1.5 wt.% Cr (1.5Cr) or Ni (1.5Ni). Additions of 1.5 wt.% Cr significantly slowed the kinetics of austenite decomposition relative to the 1.5Ni alloy at all partitioning temperatures, promoting greater austenite retention, lower retained austenite carbon (C) contents, and reduced sensitivity of the retained austenite amounts to processing variables. In the 1.5Cr alloy after partitioning at 400 °C for 300 s, η-carbides were identified by transmission electron microscopy (TEM) and atom probe tomography (APT) revealed no significant enrichment of substitutional elements in the carbides. In the 1.5Ni alloy after partitioning at 450 °C for 300 s, both plate-like and globular carbides were observed by TEM. APT analysis of the globular carbides clearly revealed significant Si rejection and Mn enrichment. Mössbauer effect spectroscopy was used to quantify the amount of carbides after Q&P. In general, carbide amounts below ∼0.3% of Fe were measured in both alloys after partitioning for short times (10 s), irrespective of quench or partitioning temperature, which corresponds to a relatively small portion of the bulk C. With increasing partitioning time, carbide amounts remained approximately constant or increased, depending on the alloy, quench temperature, and/or partitioning temperature.

在两种基本成分为0.2C–1.5Mn-1.3Si wt的钢中，研究了Cr和Ni的添加以及淬火和分配（Q＆P）工艺参数对显微组织发展的影响，包括Q＆P期间的碳化物形成和奥氏体保留。 ％和1.5重量％的Cr（1.5Cr）或Ni（1.5Ni）的添加。在所有分配温度下，相对于1.5Ni合金，添加1.5 wt。％Cr显着减慢了奥氏体分解的动力学，提高了奥氏体的保留率，降低了残余奥氏体碳（C）的含量，并降低了残余奥氏体对工艺变量的敏感性。在1.5Cr合金中于400°C分配300 s后，通过透射电子显微镜（TEM）鉴定了η碳化物，原子探针断层扫描（APT）显示碳化物中没有明显的取代元素富集。在1.5Ni合金中在450°C分配300 s后，通过TEM观察到板状和球状碳化物。球状碳化物的APT分析清楚地表明了显着的Si排斥和Mn富集。穆斯堡尔效应光谱用于量化Q＆P之后的碳化物数量。通常，在短时间（10 s）分配后，两种合金中的碳化物含量均低于Fe的0.3％，而与淬火或分配温度无关，这对应于体积C的相对较小。随着分配时间的增加，取决于合金，碳化物的数量保持大致恒定或增加，