The Iphone5 bought in China is a card of China Mobile. Can I use it for international roaming in Korea?

Hello, you need to turn on the international roaming function of the number and put it into a GSM/WCDMA dual-mode mobile phone (iPhone5 customized by non-telecom can) to use it in Korea. The specific tariffs are as follows:

You call South Korea 0.99 yuan/minute, Chinese mainland 0.99 yuan/minute, Hong Kong, Macao and Taiwan and other countries and regions 0.99 yuan/minute; Receiving SMS is free, 0.39 yuan/message or 0.44 yuan/message (depending on the brand), 1.29 yuan/message is sent to Hong Kong, Macao and Taiwan or other countries and regions; Mobile data traffic fee is charged at 0.005 yuan /KB. Tips: The above tariff standards are RMB currency units.