Allegheny Technologies Inc. says it will temporarily idle two western Pennsylvania plants next year due to low prices for specialty steel. The Pittsburgh-based steelmaker has locked out workers at 12 plants in Pennsylvania and five other states since August 15 over a contract dispute. On Thursday, the company blamed Chinese imports and a glut of global steelmaking for driving prices to levels not seen since 2003. The company says it will idle plants in Midland, Beaver County and Gilpin Township, Armstrong County next year until they can generate acceptable profits. The plants employed nearly 600 workers combined before the lockout. It’s not clear how many management and replacement workers have been keeping them running. The Midland shutdown will begin in January, and Bagdad’s in April.