On April 30, 2018, CBP issued CSMS #18-000316 Quota Announcement South Korea Steel Mill Articles.
The CSMS states:
A Presidential Proclamation for steel mill articles under section 232 of the Trade Expansion Act of 1962, as amended (19 U.S.C 1862); Iron or steel products imported into the United States, country of origin, South Korea, effective for goods entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 eastern daylight time on May 1, 2018 is subject to absolute quota.
The Trade may refer to quota bulletin (QB) 18-118 for details on South Korea absolute quota categories. Related quota information may also be found posted cbp.gov, quota page. https://www.cbp.gov/trade/quota .
Questions related to absolute quota filing requirements should be emailed to HQ QUOTA HQQUOTA@cbp.dhs.gov.