The Electropolishing of C-Steel in Orthophosphoric Acid Containing Methanolic Plant Extract

Table 4

Measured roughness (Ra), Rq (RMS), Peak-valley ratio, and brightness of C-steel samples.

Sample	EP conditions	Brightness (gloss value)	Peak-valley ratio (μm)	Ra (μm)	Rq (RMS) (μm)
A	Before electropolishing	11.1	4.8	2.7	3.4
B	After EP without additives	16.0	0.47	0.52	0.66
C	After EP + 100 ppm guava leaves	18.0	0.40	0.44	0.56
D	After EP + 500 ppm guava leaves	24.5	0.30	0.28	0.32
E	After EP + 100 ppm chamomile	18.4	0.36	0.40	0.52
F	After EP + 500 ppm chamomile	27.0	0.29	0.23	0.23
G	After EP + 100 ppm coriander seeds	19.2	0.34	0.36	0.48
H	After EP + 500 ppm coriander seeds	56.59	0.28	0.21	0.22
I	After EP + 100 ppm marjoram	21.9	0.31	0.32	0.42
J	After EP + 500 ppm marjoram	64.9	0.22	0.17	0.20