Optimum heat treatment conditions for 1Kh1SN12M2TL steel

Summary

• 1. Cast samples (not subjected to heat treatment) have unsatisfactory mechanical properties.

• 2. The optimum quenching conditions of cast articles of 1Kh18N12M2TL steel consists of heating at the rate of 230 deg/h to 1150°C. keeping the samples at this temperature for 2 h, and then quenching in water.

• 3. Stabilizing annealing for 2 h at 875°C lowers the mechanical characteristics and increases the brinleness of steels with an austenitic-ferritic structure because of the transformation of ferrite into the σ-phase.

• 4. Heating for 2 h at 650°C induces the precipitation of carbides and of the σ-phase. However, after quenching under optimum conditions the distribution of these precipitates is favorable and does not induce susceptibility to embrittlement or intercrystalline corrosion.

• 5. Nonmetallic inclusions (oxides, silicides, nitrides) have a significant effect on the mechanical properties of the steel and on its susceptibility to intercrystalline corrosion. It is impossible to eliminate their influence by heat treatment, and therefore it is necessary to take measures during smelting and pouring to increase the degree of utilization of titanium and prevent the contamination of the steel with nonmetallic inclusions.