*3.2. Weight Loss Tests*

Figure 7 shows the Δ*W* (mg cm−<sup>2</sup> h<sup>−</sup>1) and *P*<sup>w</sup> (mm y<sup>−</sup>1) values of the cast ZK60 alloy immersed in 0.1 M NaCl for different times (t). The *P*<sup>w</sup> at 24 h was the largest (3.5 <sup>±</sup> 0.1 mm y−1), which is similar to that of a cast ZK60 in 0.9% NaCl (4.6 <sup>±</sup> 0.6 mm y−1) reported by Merson et al. [52]. Then, it gradually decreased by approximately half to a relatively stable value (1.4~1.7 mm y<sup>−</sup>1) over 72–96 h. The decrease in *P*w over 72–96 h may have been related to the increase in the corrosion product layer Mg(OH)2 on its surface [53].

**Figure 7.** Corrosion rates (Δ*W* and *P*W) of the cast ZK60 alloy after immersion in 0.1M NaCl for different times measured by weight loss tests.
