Imperfect elasticity of steel Kh15N27T3MR

Conclusions

• 1. To obtain the minimal values of the characteristics of imperfect elasticity of precipitation-hardening spring steel Kh15N27T3MR we recommend quenching from 1050° and tempering at 750° for 5 h for the steel not strain hardened and at 700° for 5 h, 700° for 2 h, and 700° for 1 h for the steel deformed 17, 30, and 60%, respectively.

• 2. Plastic deformation of steel Kh15N27T3MR after quenching substantially increases its elastic limit and reduces distortion of the elastic aftereffect, especially during subsequent tempering. In this case strain hardening accelerates precipitation hardening processes.

• 3. For the strain hardened steel the elastic limit decreases at a higher rate and the distortion of the elastic aftereffect increases at a higher rate with increasing testing temperatures. The larger the strain hardening, the more notable this effect.

• 4. Plastic deformation does not change the shear modulus of quenched samples; it increases 6% with tempering. The temperature coefficient of the modulus of elasticity remains constant up to 700°.

• 5. From the results of the investigation we recommend the following maximum operating temperatures for elastic elements made of steel Kh15N27T3MR; 600° for the quenched and tempered steel; 500° for the steel deformed 17 and 30% after quenching; 400° for the steel deformed 60%.