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How does 304 material get rust
Jan 22, 2018

Causes that 304 material get rust might been as the following

1. Presence of chloride ions in the using environment

Chlorine ions exist extensively in substances like salt, sweat trace, seawater, sea breeze, soil, etc. Stainless steels corrode rapidly in chloride ions contained environment, even faster than common low carbon steels.

So there are requirements on stainless steel using environment. It needs frequent wiping to get rid of the dust and keep dry and clean.

2. No Solution Treatment

The alloy elements were not dissolved into the matrix, which resulted in low alloy content and poor corrosion resistance.

3. This kind of material with no titanium and niobium has a natural tendency of inter-granular corrosion. With the adding of titanium and niobium, and then the stabilization treatment to reduce the inter-granular corrosion.

A kind of high alloy steel which can resist corrosion in air or chemical corrosion medium. Stainless steel has beautiful surface and good corrosion resistance. The surface property of stainless steel is used in many aspects of steel, which is usually called stainless steel. On behalf of the properties of High alloy steels like 13 chromium steel, 18-8 chromium nickel steel can be on behalf of its properties.

Analyzing from the metallography angle, the thin chromium film formed on the surface because of the chromium is contained in the stainless steel. This film isolates the oxygen from invading into the steel and acts as a corrosion resistance.

In order to maintain the inherent corrosion resistance of stainless steel, the steel must contain chromium of more than 12%.

304 is a kind of universal stainless steel widely used in the manufacture of equipment and machine parts which require good comprehensive properties (corrosion resistance and moldability).

304 stainless steel is a grade of stainless steel produced in accordance with the ASTM standard of the United States. 304 is equivalent to 0Cr19Ni9Ti stainless steel in China. 304 contains 18% chromium, 9% nickel and carbon no more than 0.08%.

304L is a variety of 304 stainless steel with low carbon content, which is used for places need welding. Low carbon content minimizes the precipitation of carbides in the heat-affected zone near the welding seam. The precipitation of carbides may lead to inter-granular corrosion (welding erosion) of stainless steel in some environments.







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