The new plastic mold steel is typically supplied in the hardened-and-tempered condition at approximately 290 to 330 HB, corresponding to about 32 HRc. In this way, a good combination of machinability, hardness and wear resistance is given.

To examine the corrosion resistance, salt spray tests were carried out according to DIN 50021, It was found that the corrosion attack was minimized after 2, 4 and 6 hours with the new alloy in comparison to the common 1.2316, which is also a positive result of the homogeneous microstructure.

Furthermore both alloys were tested in pitting corrosion measurements. The test medium used was synthetic seawater adjusted to the pH value of 4 using HCl. The pitting potential measured at room temperature of the new nitrogen alloyed prehard stainless is as good—if not better than—1.2316.

Improvements in productivity lead to a reduction in cycle time during plastics processing. As a consequence, plastic mold steels with a higher thermal conductivity are required.

The thermal conductivity of the N-alloyed prehard stainless and the classic prehardened modified 420 stainless alloy was investigated in the temperature range between 20°C and 500°C.

To determine the influence of the homogenous microstructure of the new alloy on its machinability, a series of tests were done. The machinability of the classic 420 stainless alloy and the new alloy has been tested by rough milling, end milling, drilling, and gun drilling and tapping.