Godec M, Večko Pirtovšek T, Šetina Batič B, McGuiness P, Burja J, Podgornik B
Institute of Metals and Technology, Lepi pot 11, 1000 Ljubljana, Slovenia.
Metal Ravne d.o.o., Koroška cesta 14, 2390 Ravne na Koroškem, Slovenia.
Sci Rep. 2015 Nov 5;5:16202. doi: 10.1038/srep16202.
We have studied the transformation of carbides in AISI M42 high-speed steels in the temperature window used for forging. The annealing was found to result in the partial transformation of the large, metastable M2C carbides into small, more stable grains of M6C, with an associated change in the crystal orientation. In addition, MC carbides form during the transformation of M2C to M6C. From the high-speed-steel production point of view, it is beneficial to have large, metastable carbides in the cast structure, which later during annealing, before the forging, transform into a structure of polycrystalline carbides. Such carbides can be easily decomposed into several small carbides, which are then randomly distributed in the microstructure. The results also show an interesting difference in the carbide-transformation reactions on the surface versus the bulk of the alloy, which has implications for in-situ studies of bulk phenomena that are based on surface observations.
我们研究了AISI M42高速钢在锻造温度范围内碳化物的转变。发现退火会导致大型亚稳M2C碳化物部分转变为较小、更稳定的M6C晶粒，同时晶体取向也会发生相关变化。此外，在M2C向M6C转变过程中会形成MC碳化物。从高速钢生产的角度来看，铸态组织中存在大型亚稳碳化物是有益的，这些碳化物在退火过程中，即在锻造之前，会转变为多晶碳化物结构。这种碳化物可以很容易地分解成几个小碳化物，然后随机分布在微观结构中。结果还表明，合金表面与整体的碳化物转变反应存在有趣的差异，这对基于表面观察的整体现象原位研究具有启示意义。
