4872
Both AM and conventional stainless steel 316L samples were examined in NaCl 3.5 % solution before and after the annealing process using Tafel curves , Electrochemical Impedance Spectroscopy , and X-ray diffraction .
 AM, stainless steel, samples, NaCl, solution, annealing, Electrochemical, Spectroscopy, X-ray diffraction
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 AM, stainless steel, samples, NaCl, solution, annealing, Electrochemical, Spectroscopy, X-ray diffraction