Modification of metastable microstructure of CPM15V steel by heat exposure after treatment in semi-solid state
Modification of metastable microstructure of CPM15V steel by heat exposure after treatment in semi-solid state
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DOI：
10.1016/j.jallcom.2013.04.064
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发表时间：
2014-02
影响因子：
6.2
通讯作者：
Filip Vančura;B. Mašek;D. Aišman;H. Jirková;M. Wagner;M. Böhme
中科院分区：
文献类型：
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作者：
Filip Vančura;B. Mašek;D. Aišman;H. Jirková;M. Wagner;M. Böhme
在半固态状态下加工可以将成形和铸造工艺的优点结合起来。除了获得复杂的形状外，还可以形成具有特殊性质的特殊结构形式。开发了一种特殊的小零件半固态加工工艺，即微触变成形，能够处理CPM15V钢粉。在原铁素体基体上，经加工得到了亚稳奥氏体、棒状铬钒碳化物和原铬钒碳化物的混合结构。与初始状态(显微硬度约为。HV10 330)，这种结构实现了，由于在形式中相对较高的冷却速率，硬度约为。730 HV10。由于这是一个亚稳结构，实验加热到400、500、600、700、800℃1小时。暴露在400和500°C的温度下，硬度略有下降，约为。20分，600℃热处理，硬度达到960 HV10。这种状态对应于抗压强度的等效值约为。2880 MPa时，温度进一步升高，亚稳基体分解导致硬度持续下降。热暴露在700°C，导致硬度585 HV10。暴露于800°C后，硬度显著降低至425 HV10。
Processing in the semi-solid state allows the benefits of the process of forming and casting to be combined. In addition to obtaining complicated shapes, unusual forms of structures with exceptional properties can also be formed. A special processing procedure in the semi-solid state for very small parts has been developed, which is called mini-thixoforming, is able to handle CPM15V steel powder. From the original ferrite matrix with primary chromium–vanadium carbides – a mixed structure was obtained by processing consisting of metastable austenite, rod-shaped chromium–vanadium carbides and the original chromium–vanadium carbides. Compared to the initial state (micro hardness approx. HV10 330), this structure achieved, as a result of the relatively high rate of cooling in the form, a hardness of approx. 730 HV10. Due to the fact that this is a metastable structure, experimental heating to temperatures 400, 500, 600, 700, 800 °C for 1 h was performed. With exposure at temperatures 400 and 500 °C there was a slight decrease in hardness of approx. 20 points, heat treatment at 600 °C achieved hardness of 960 HV10. This state corresponds to an equivalent value of compressive strength of approx. 2880 MPa, Further increase in temperature leads to a continuous decrease in hardness due to decomposition of the metastable matrix. Thermal exposure at 700 °C, resulted in hardness of 585 HV10. After exposure to 800 °C there was a significant decrease of hardness to 425 HV10.