Mechanical and magnetic properties of cast irons VCh 50-2 and KCh 50-5 after temper hardening

Conclusion

After heat treatment cast iron changes both its mechanical and magnetic properties, which is connected with structural transformations in the matrix. Thus, from results of the change in magnetic properties for cast iron, it is possible to estimate the amount of heat treatment, i.e., to establish the structural and phase condition of the cast iron, and to estimate the completeness of transformations occurring during quenching and tempering.

As parameters for monitoring the heat treatment of HCSG and PMC in the tempering range 600–750°C, it is possible to use$H_{\mu _{\max } }$ and µ₃₀₀, and µ₃₀₀ is to be preferred. In the range t_tem=500–600°C$H_{\mu _{\max } }$ should be used.

Results of these studies have been used in developing an electromagnetic structurescope by means of which measurements have been made of differential dynamic magnetic permeability for monitored and reference articles located in continuous eddy-current converters.

Test for a structurescope under production conditions at the Volga Automobile Factory during quality control of temper hardening for PMC and HCSG castings demonstrated its high efficiency, reliability and productivity.