| Title |
A study on the chemical surface Treatment of Alloy Tool Steel Effect of Na2SO4 and NaCl on Case hardening of Alloy Tool Steel in Carbo - Nitriding |
| Abstract |
A method of case hardening treatment on the alloy tool steel (SKD-11) have been studied by using molten salt bath composed of K₄Fe(CN)_6, NaOH, Na₂SO₄ and NaCl where the weight ratio of major two compounds was fixed to 88 : 8.5 but those of Na₂SO₄ and NaCl were varied in the range of 0-3.5%. The experiments were conducted in the molten salts at 550℃ for various periods of time and different salt compositions have lead to the following: The significance in the weight ratio of Na₂SO₄ is recognized considerably and the optimum condition of treatment is obtainable when Na₂SO₄ content in the bath is as much as 2.0% and soaking for 90 minutes. In the optimum condition of treatment the effective thickness and hardness of hardened layer attainable is respectively 111μ and Hv 620. |