Diffusion boriding of steel 40Kh in a powered mixture with high activity

1. A high rate of formation of a biphase boride coating (80–90μ) was attained in the first hour of boriding steel 40Kh in a mixture of 80% B+16% Na2B4O7+4% KBF4. 2. The boride coatings obtained in this mixture with holding for 2–6 h are even and dense with no peeling and low brittleness, due to the use of relatively low processing temperatures. 3. Reducing the percentage of FeB phase in the coating reduces the probability of cracking. 4. The powdered mixture of 80% B+16% Na2B4O7+4% KBF4 is suitable for production and can be recommended for boriding steels.