Ãâó : http://www.koreawelding.org/common/download.html?service=board&dir=201710&fileName=%EB%A0%88%EC%9D%B4%EC%A0%80%EC%9A%A9%EC%A0%91%EC%97%90+%EC%9D%98%ED%95%9C+%EA%B8%88%EC%86%8D%EA%B5%AC%EC%A1%B0%EB%AC%BC%EC%9D%98+%EC%A0%81%EC%B8%B5%EA%B0%80%EA%B3%B5+%EA%B8%B0%EC%88%A0.pdf&source=a29a5ba2cb7bdeabba22de8c83321b46.pdf