A formed steel part includes a first steel plate having a first base, a first intermetallic alloy layer on the first base and a first metal alloy layer on the first intermetallic alloy layer, the first steel part having a first area without the first metal alloy layer and having at least part of the first intermetallic alloy layer; and a second steel plate having a second base, a second intermetallic alloy layer on the second base and a second metal alloy layer on the second intermetallic alloy layer, the second steel part having a second area without the second metal alloy layer and having at least part of the second intermetallic alloy layer in the second area. The first and second steel plates are joined together. The formed steel part may also include a butt-weld joining the first and second steel plates.