The 20th Shanghai Aisen Welding and Cutting Exhibition in 2015 The 20th Shanghai Aisen Welding and Cutting Exhibition in 2015 The 20th Shanghai Aisen Welding and Cutting Exhibition in 2015 The 20th Shanghai Aisen Welding and Cutting Exhibition in 2015 The 20th Shanghai Aisen Welding and Cutting Exhibition in 2015 The 20th Shanghai Aisen Welding and Cutting Exhibition in 2015 The 20th Shanghai Aisen Welding and Cutting Exhibition in 2015 The 20th Shanghai Aisen Welding and Cutting Exhibition in 2015