In response to weakening end-use market demand for steel in the wake of the global coronavirus outbreak, ArcelorMittal is takina steps to scale back its North American output, a spokesman for the company said.ArcelorMittal's Indiana Harbour mill has begun preparations to blow down the No. 4 blast fumace, according to the company. To blow down a furnace, iron and slag continues to be produced, but no raw materials are added urtil the upper part of the BF is emptyThe entire Indiana Harbor complex has approximately 6.4 million st of annual steelmaking capacity, according to a company fact sheet.Separately. ArcelorMittal is also reducing production at its Dofasco mill in Hamilton, Ontario, in response to weakening end markets, the company said. As a result, AM Dofasco has bequn the temporary blow down of the No. 3 BF at the facility as a precaution to preserve the asset for future production, the company said.The No. 3 BF at Dofasco has an annual rated capacity of 789.250 st and is the smallest of the three blast furnaces at the facility, according to data from the Association for Iron and Steel Technology.ArcelorMittal Dofasco ships 4.5 million st of steel annually, according to the company's website.