The stainless steel hot-rolling, about thick.2mm. The steel plate is solidified and bulging occurs.
The gold phase test found welding tissues in the condensed surface, but no welding traces were found from the steel plate surface.
I think it is the steel has surface defects and welding has been done, but the welding is significantly different from the mother's composition, and the welding tissue is preserved despite heating.

Figure1.16-1Welding without stain. Trichloride water solution erosion 50×
The following are the products that will be used for gold phase:
1. FY-QG-65, a Fuyunkin co-moder, cut the sample gold and cut down a small piece, horizontal or vertical, as required by the sample, to facilitate mosaicing.

II. Kim Co-simworks:
Fuyun materials gold-specific sandpaper: 230mm diameter without glue 600# 1200# 2500#

III. LEAVE THE FIELDS OF THE KING PHOTOS:
Fuyun materials gold-phased photo fabric: 230 mm in diameter velvet/splendon
Fuyun materials, Fresco-Frestilt Spraying: 1/3 micrometre
Fuyun machine: manual in no-extreme-speed grinder
Pressure: Fixed, neutral, stable, without too much pressure.
Time: 2-5 minutes, whichever is the same, the scratches of the thin sandpaper are almost removed.
Rotation speed: 200 turns
Raarboard direction: Clockwise
During polishing: The polished rags need to be immersed early, the polished fluid is down in the centre position and handwashing is added to its lubrication.
Pour: A little bright, no scratches, and can move on.
During polishing: The polished rags need to be immersed early, the polished fluid is down in the centre position and handwashing is added to its lubrication. 
Pouring: The brightness is very high.
Corrosion observation:
Fuyun gold microscope (magnification multiple: 50X, 100X, 200X, 500X, 1,000X)

The following are used for corrosive reagents:

