Tarasenko

The paper examines a possibility to apply the ÈP 678 and ÈP 817 martensitic-aging steels to manufacture the force-measuring resilient member in electronic strain-gauge balance. It proposes to use double aging, namely main and low-temperature one as a hardening heat treatment after hardening. Microstructure, X-ray microanalysis, X-ray diffraction, potentiodynamic researches have been conducted, and structure and properties of hard-ended samples after main and double aging have been compared. It is established, that double aging causes extra hardening of steels, but it has a different influence on corrosion resistance of steel, namely the corrosive properties of AP817 steel containing copper are improved due to formation of uniformly distributed cathode ε-Cu corpuscles; the corrosive properties of AP678 steel are deteriorated because of increased heterogeneity of structure.

 The authors study the effect of welding heat to corrosive properties of maraging steel, the influence of chemical composition of steel on liability to intergranular corrosion; they set a method of improving corrosion resistance of welds by use of surface treatment.