BEIJING — Treasury Secretary Jack Lew chided China on Monday for allowing a glut of steel and aluminum to flood global markets, and urged Beijing to treat foreign companies with the same openness that Chinese firms often receive across the world.

The annual U.S.-China Strategic and Economic Dialogue is usually an occasion when the two sides try to highlight areas of cooperation and progress. But this year’s event in Beijing is overshadowed by growing trade and commercial friction, as well as continued sparring over China’s efforts to exert greater control over the South China Sea…