Correct

平炉

/ píng lú / 
Strokes

Example

As a Noun

open hearth; open-hearth furnace; Martin furnace

1
Pínglú
平炉
zhā
渣

open-hearth slag

2
Pínglú
平炉
liàngāng
炼钢
fǎ
法

open-hearth process

3
Pínglú
平炉
gāng
钢

open-hearth steel