Borochromized coatings on 5CrNiMo steel were prepared by thermo-reactive diffusion in a molten borax salt bath at 1173 K, 1223 K, and 1273 K for 0.5–6 h. The cross-sectional observation of optical microscopy (OM) revealed that the as-obtained coatings possessing a comb-like or needle-like microstructure with 21.4–84.7 µm thickness were smooth, compact, and homogeneous. X-ray diffractometry (XRD) results expressed that the borochromized coatings mainly consisted of FeB, Fe₂B, Cr₅B₃, and a small amount of M₇C₃ (M–Cr, Fe) and α-Fe(Cr). B₄C, as a boron-donating agent, first reacted with NaF (activator) to produce active boron atoms and then reduced Cr₂O₃ (chromium-donating agent) to generate active chromium atoms, whereas borax was only used as the base salt or heating medium in the present experiment. The activation energy of the as-prepared borochromized coating on 5CrNiMo steel was calculated as 161 kJ/mol.

通过在熔融硼砂盐浴中于1173 K，1223 K和1273 K上进行0.5-6 h的热反应扩散，可以制备5CrNiMo钢上的渗铬涂层。光学显微镜（OM）的横断面观察显示，所获得的涂层具有梳状或针状微观结构，厚度为21.4–84.7 µm，是光滑，致密且均匀的。X射线衍射（XRD）结果表明，硼化涂层主要由FeB，Fe ₂ B，Cr ₅ B ₃和少量的M ₇ C ₃（M–Cr，Fe）和α-Fe（Cr）组成。 。B ₄ C作为供硼剂，首先与NaF（活化剂）反应生成活性硼原子，然后还原Cr ₂ O₃（供铬剂）生成活性铬原子，而硼砂在本实验中仅用作基础盐或加热介质。经计算，在5CrNiMo钢上制备的硼铬化涂层的活化能为161 kJ / mol。