Tęcza Grzegorz
Department of Cast Alloys and Composites Engineering, Faculty of Foundry Engineering, AGH University of Science and Technology, 30 Mickiewicza Ave., 30-059 Krakow, Poland.
Materials (Basel). 2023 Feb 19;16(4):1726. doi: 10.3390/ma16041726.
Cast austenitic chromium-nickel steel is commonly used for the manufacture of machine parts and components, which are exposed to the attack of corrosive media and abrasive wear during operation. The most commonly used grades include GX2CrNi18-9 and X10CrNi18-8 as well as GX2CrNiMo17-12-2 and X6CrNiMoNb17-12-2. To improve the abrasion resistance of cast chromium-nickel steel, primary niobium carbides were produced in the metallurgical process by increasing the carbon content and adding Fe-Nb. The microstructure of the obtained test castings consisted of an austenitic matrix and primary niobium carbides evenly distributed in this matrix. The measured hardness of the samples after heat treatment ranged from 215 to 240 HV and was higher by about 60 units than the hardness of the reference cast GX10CrNi18-9 steel, which had a hardness of about 180 HV. Compared to the reference cast steel, the abrasive wear resistance of the tested cast chromium-nickel steel (measured in Miller test) with contents of 4.4 and 5.4 wt% Nb increased only slightly, i.e., by 5% for the lower niobium content and 11% for the higher niobium content. Compared to ordinary cast GX10CrNi18-9 steel, the addition of 9.2 wt% Nb reduced the abrasive wear by almost 2.5 times.
铸造奥氏体铬镍钢通常用于制造机器零件和部件，这些零件和部件在运行过程中会受到腐蚀性介质的侵蚀和磨料磨损。最常用的钢种包括GX2CrNi18-9和X10CrNi18-8以及GX2CrNiMo17-12-2和X6CrNiMoNb17-12-2。为提高铸造铬镍钢的耐磨性，在冶金过程中通过增加碳含量和添加Fe-Nb生成了初生碳化铌。所获得的试验铸件的微观组织由奥氏体基体和均匀分布在该基体中的初生碳化铌组成。热处理后样品的实测硬度为215至240 HV，比参考铸造GX10CrNi18-9钢的硬度（约180 HV）高出约60个单位。与参考铸钢相比，铌含量为4.4 wt%和5.4 wt%的试验铸造铬镍钢（在米勒试验中测量）的耐磨性能仅略有提高，即铌含量较低时提高了5%，铌含量较高时提高了11%。与普通铸造GX10CrNi18-9钢相比，添加9.2 wt%的铌使磨料磨损降低了近2.5倍。
