230V/230V AC relay circuit
Due to inductive spikes mainly if the relay contacts open during the peak current portions of the AC cycle, I would suggest an MOV (metal oxide varistor) across the contacts of the first relay. Alternatively you could place it across the load (the coil of the second relay). The MOV should be rated for at least 275Vrms (such as Littelfuse V275LA2P). If the final load is inductive, you should place one there also (or one each across each contact of the second relay).

A snubber is often used when switching AC inductive loads and could be used here as well as (or in place of) the MOV. This is made of a resistor and capacitor in series which will slow the rise time of and attenuate the inductive spikes. Red Lion makes a snubber (SNUB0000) or you can make your own. Note that an MOV will clip the inductive spike while a snubber will also slow the rise-time and thus greatly reduce interference with other equipment. From the Red Lion datasheet:


  The R-C Snubber is intended to suppress the “inductive kick” from motors,
  solenoids or relay coils. High energy noise spikes are generated whenever
  current is interrupted through an inductive load. These noise spikes may
  interfere with associated equipment causing erratic operation and may also
  accelerate relay contact wear. Applied across an inductive load, the R-C
  snubber suppresses the noise spikes and extends contact life.


I agree with Andyaka's comment: "Why don't you find a single relay that can do the job?"; although due to your specific circumstances, two relays also make sense.