Atom Probe Tomography of Carbides in Fe-Cr-(W)-C Steels
Atom Probe Tomography of Carbides in Fe-Cr-(W)-C Steels
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Fe-Cr-(W)-C 钢中碳化物的原子探针断层扫描
DOI：
10.1002/srin.201900107
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发表时间：
2019
影响因子：
2.2
通讯作者：
Gramlich A
中科院分区：
文献类型：
--
作者：
Gramlich A
在这项研究中，Fe-Cr-C和Fe-Cr-W-C合金的特征在于使用原子探针断层扫描。将合金在1070 °C下热处理30分钟，随后在780 °C下热处理不同的时间段。在每个状态下观察到碳化物形成。对于短的热处理时间，观察到半径小于5 nm的Cr-C沉淀物，并且对于大于1000 s的热处理时间，观察到半径大于50 nm的Cr-C沉淀物。发现在第一时间段内，相界面以几乎恒定的速度移动。随后相界面的速度减小。此外，从以前的理论研究碳化物生长的动力学假设已被验证。正如预期的那样，随着时效时间的增加，检测到马氏体回火引起的显微硬度下降。本研究的目的是测量基体和沉淀物之间的相界面的化学成分的变化，以更好地了解沉淀过程。
In this study, Fe‐Cr‐C and Fe‐Cr‐W‐C alloys are characterized using atom probe tomography. The alloys have been heat treated at 1070 °C for 30 min and subsequently at 780 °C for various time periods. Carbide formation is observed at each state. Cr‐C precipitates smaller than 5 nm in radius for short heat treatment times and larger than 50 nm for heat‐treatment times greater than 1000 s are observed. It is found that the phase interface moves during the first time period at an almost constant speed. Later on the velocity of the phase interface decreases. Furthermore, kinetic assumptions for carbide growth from a previous theoretical study have been verified. As expected, a decrease of the microhardness with increasing aging time is detected which is caused by martensite tempering. The aim of this study is to measure the change in chemical compositions across phase interfaces between matrix and precipitates to obtain a better understanding of the precipitation process.