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用表面机械磨损处理(SMAT)在AISI H13钢上制备一层纳米结构的表面层。研究了这种SMAT试样的渗硼性能和粗晶粒对应物的比较。SMAT试样的硼扩散深度在600℃,2 h渗硼后的峰值是8μm,比粗晶粒试样深得多。在SMAT试样上用600℃接着更高温度的双重渗硼处理能合成厚得多的渗硼层。而且SMAT试样的活化能是1403 kJ/mol,比粗晶粒的209.4 kJ/mol低得多。结果表明,用双重渗硼处理的SMAT试样能明显增强渗硼动力学。而且热疲劳试验表明,具有优良抗氧化性和高温机械强度的渗硼层能有效延迟热疲劳裂纹的萌生,阻碍它们的传播。所以经双重渗硼处理的H13钢的热疲劳性能可以大大提升。
A surface nanostructured surface layer was prepared on AISI H13 steel using Surface Mechanical Wear Treatment (SMAT). The boronizing properties of this SMAT sample were compared with those of the coarse-grained counterparts. The diffusion depth of boron in SMAT sample is 600 ℃, the peak value after 2 h boronizing is 8μm, which is much deeper than that of coarse grain sample. A much thicker borided layer can be synthesized on a SMAT coupon with a dual boronizing treatment at 600 ° C followed by a higher temperature. Moreover, the activation energy of the SMAT sample is 1403 kJ / mol, much lower than 209.4 kJ / mol of the coarse grain. The results show that the dual boronizing SMAT sample can significantly enhance boronizing kinetics. Moreover, the thermal fatigue test shows that the boronizing layer with excellent oxidation resistance and mechanical strength at high temperature can effectively retard the initiation of thermal fatigue cracks and hinder their propagation. Therefore, the double boronizing H13 steel thermal fatigue properties can be greatly enhanced.