3M reported second-quarter earnings of $2.02 per share, an increase of 5.8% versus the second quarter of 2014. Sales declined 5.5% year-on-year to $7.7 billion. Organic local-currency sales grew 1.8% and foreign currency translation reduced sales by 7.3% year-on-year.   Operating income was $1.8 billion and operating income margins for the quarter were 23.9%, up 1.1 percentage points year-on-year. Second-quarter net income was $1.3 billion and the company converted 74% of net income to free ca...