Evaluation of microstructures and mechanical properties of chromized steels with different carbon contents
Evaluation of microstructures and mechanical properties of chromized steels with different carbon contents
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DOI：
10.1016/j.surfcoat.2003.08.031
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发表时间：
2004-01
影响因子：
5.4
通讯作者：
Jyh-Wei Lee;J. Duh
中科院分区：
文献类型：
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作者：
Jyh-Wei Lee;J. Duh
渗铬工艺是一种用于开发具有硬度、耐磨性和耐腐蚀性的表面涂层的方法。三种碳钢，AISI 1020、1045和1095，含0.20、0.45和1.0重量%在950 °C下，用包埋渗铬工艺分别渗铬1、4和9 h。渗铬表面的初生相为（Cr，Fe）2N 1 − x，其余为（Cr，Fe）23 C6相。渗铬层厚度服从抛物线规律：X=K_t，随渗铬时间和基体碳含量的增加而增加。计算出AISI 1020、1045和1095的抛物线速率常数K分别为4.04、7.25和8.43 μm/μ m·h。渗铬层的纳米硬度为18 GPa，这归因于表面上的（Cr，Fe）2N 1 − x相。渗铬AISI 1020钢的临界载荷的下限和上限值随渗铬时间的增加而降低，而渗铬AISI 1045和1095钢的临界载荷随渗铬时间的增加而增加。由于镀铬表面上较厚的（Cr，Fe）2N 1 − x相，可实现高临界载荷和足够的粘附性能。
Chromization process is a method for developing a surface coating providing hardness, wear and corrosion resistance. Three carbon steels, AISI 1020, 1045 and 1095 with 0.20, 0.45 and 1.0 wt.% carbon contents, respectively, were chromized with pack cementation process at 950 °C for 1, 4 and 9 h. The primary phase on the chromized surface is (Cr,Fe)2N1−xand the rest is (Cr,Fe)23C6phase. The thickness of the chromized layer obeys the parabolic rate law: X=K√t and increases with chromization time and carbon contents in the matrix. The parabolic rate constants K are evaluated to be 4.04, 7.25 and 8.43 μm/√h for AISI 1020, 1045 and 1095, respectively. The nanohardness of the chromized layer is 18 GPa, which is attributed to the (Cr,Fe)2N1−xphase on the surface. Values of lower and upper critical loads of the chromized AISI 1020 steel decrease with increasing chromization time, whereas the increasing critical loads with chromizing time are observed on the chromized AISI 1045 and 1095 steels. High critical loads and sufficient adhesion properties are achieved due to the thicker (Cr,Fe)2N1−xphase on the chromized surface.