How to recognize the product is the standard 304 stainless steel stainless?
On the market there are three common types of stainless steel materials: stainless steel 304 (18/10: 18% of components containing chromium and 10% nickel), stainless steel 201 (18/8) and 430 stainless steel (18/0). Type 304 stainless steel with high gloss levels, relatively clean, not rusty, so its cost is quite high. 201 stainless steel nickel in the composition ratio lower, 430 stainless steel containing iron and other impurities. 201 and 430 stainless steel thus susceptible rusty, low reliability, not safety, their cost is much lower than 304 stainless steel.
However, due to high costs and much of chasing profits, many products now appears rampant in the market with material made of stainless steel 201 and stainless steel 430. So how to distinguish what is the 304 stainless steel materials used and what is the use of other materials? Indeed it is difficult to distinguish with the naked eye. If the experiment with magnets you can easily distinguish 430 stainless steel with stainless steel remaining from a very high absorption.
1. Stainless steel 304
2. Classification of stainless steel
However SUS304 or SUS 301 if processed with high pressure at room temperature to shape (eg Forming such as the sink) is an organizational unit of materials converted to martensite, while will appear magnetic phenomena (drought, technically called from Hoa Vietnam). This phenomenon does not appear in the material SUS316. In some products, such as medical instruments requiring not to occur from the instrument turned on after the completion of processing to heat treatment at a temperature of 770 degrees Celsius to lose magnetism.
with 201 and 304 stainless steel test how best to use acid or dedicated reagents. When using acid, 304 stainless steel almost no reaction, 201 stainless steel and can be effervescent reaction occurs. Dedicated reagent usage makes it easy to distinguish by color: red brick change response is 201 stainless steel, 304 stainless steel is gray.