Before cleaning, the scorch marks left by laser cutting.

Zoom in :

Observe with a microscope:

Put into the stainless steel oxide cleaner SMC04. 

Immersion in stainless steel oxide cleaner SMC04 at 60°C for 30 seconds can effectively remove the scorch marks.

Repeat the test. Soaking in stainless steel oxide cleaner SMC04 at 60°C for 30 seconds can effectively remove the scorch marks. The left side of the photo below is soaked SMC04, 60 ℃, 30 seconds; the right side is not soaked.  

conclusion:
5.1 Soak in stainless steel oxide cleaner SMC04 at 60°C for 30 seconds, which can effectively remove the scorch marks left by laser cutting.

Before washing. The residual dirt inside the nozzle head.

Soak in stainless steel oxide cleaner SMC04 (pH 5.0), about 30 minutes and flush it with water. The left side of the picture below is after cleaning with SMC04. The picture on the right below shows the use of another rust remover.