In an embodiment, a polycrystalline diamond compact (“PDC”) comprises a cemented carbide substrate including a first cemented carbide portion exhibiting a first concentration of chromium carbide and a second cemented carbide portion bonded to the first cemented carbide portion and exhibiting a second concentration of chromium carbide that is greater than the first concentration. The PDC further comprises a polycrystalline diamond (“PCD”) table bonded to the first cemented carbide portion. The PCD table includes a plurality of bonded diamond grains exhibiting diamond-to-diamond bonding therebetween, with the plurality of bonded diamond grains defining a plurality of interstitial regions. The PCD table includes chromium present in a concentration less than about 0.25 weight %.