Posco union targets hot-rolling mills in 120-hour second partial strike

Posco's union has turned its sights on the steelmaker's hot-rolling mills for a second partial strike, shifting from the limited scope of its first action to target one of the most critical stages in the production process. The duration has also grown — from 48 hours to 120 hours — signaling that the labor-management standoff is cutting deeper into the factory floor.

According to the steel industry, the dispute committee of the Posco labor union, affiliated with the Federation of Korean Trade Unions' metal workers' federation, issued "Dispute Committee Directive No. 9" to its members Monday, announcing a 120-hour second partial strike beginning at 7 a.m. Wednesday.

The strike targets the No. 2 hot-rolling mill at Posco's Pohang steelworks and the No. 4 hot-rolling mill at its Gwangyang steelworks. Operations and maintenance workers at those facilities and all affiliated union members are to halt work entirely and join the strike. Reheating furnace operators and maintenance staff, however, are exempt. Reheating furnaces are high-temperature, gas-fed installations that require separate operational management even when a production line is shut down.

The second strike carries greater weight in production terms than the first, which ran from Wednesday through Friday last week and targeted the No. 2 electrical steel sheet mill's 3ZRM line at the Pohang steelworks and the pickling plant at the Gwangyang steelworks.

Hot rolling occupies the backbone of a steelworks' production chain. The process takes molten iron from the blast furnace through steelmaking and continuous casting to produce slabs, which are then reheated and rolled thin into hot-rolled coils. The resulting hot-rolled material is sold directly but also feeds downstream processes such as cold rolling and plating. A prolonged disruption to hot-rolling operations can therefore ripple through to finished product output as well.

The union has also left the door open to widening the strike depending on how negotiations unfold. The dispute committee stated in the directive that it would expand the number of sites covered by the second partial strike from Friday "depending on the progress of negotiations and the company's response."

The union has also tightened controls on strike participation. Members subject to the strike must check in at the union office in person every day during the walkout. Those who fail to appear will be denied strike compensation of 300,000 won ($223), while members who check in but then report to work or perform duties will be disqualified from compensation and referred to a disciplinary committee.

Substitute work and operational support at struck facilities are also prohibited. Members who receive requests from the company to provide support or perform substitute duties at those sites are required to report immediately to the dispute committee.

The union has directed members to work normal shifts through the night shift Tuesday. If the company decides to halt the line without deploying replacement workers, members are to follow dispute committee guidelines — carrying out the standard safety shutdown procedure from 6 a.m. Wednesday before leaving. The second partial strike is set to end at 7 a.m. Sept. 21, after which affected members will return to normal work schedules.

The decision puts into action an escalation the union had previously signaled. Union Chairman Kim Sung-ho had warned ahead of the first strike that "if the company continues to ignore workers' voices after the first strike, we will immediately and dramatically expand the scale and scope of the strike to deal a decisive blow to management."