In fact, the content of chromium and nickel is 304 stainless steel, and the composition contains 18% chromium (Cr) and 8% nickel (Ni), but the main difference lies in the carbon content.

304, 304L, 304H chemical composition (%) table.

304L is an ultra-low carbon stainless steel. The carbon content is reduced to less than 0.03%, which can avoid intergranular corrosion. In theory, the effect of stress corrosion resistance is stronger than that of 304, but the effect is not obvious in practical applications. The purpose of reducing carbon and adding titanium is the same, but the smelting cost of titanium-added 321 is higher, the molten steel is thick, and the price is more expensive.

The H in 304H refers to high temperature. High carbon content is the guarantee of high temperature strength. GB150 requires that when austenitic steel is used above 525 degrees, the carbon content should not be less than 0.04%. Carbide is a strengthening phase, especially high temperature strength. Better than pure austenite.

Among the three, the highest carbon content is 304H, the lowest carbon content is 304L, and the carbon content of 304 stainless steel is between the two. The higher the carbon content, the worse the corrosion resistance of stainless steel and the easier it is to rust. The difference in carbon content also causes the price to be different, or the requirements for different uses are different.

In addition, from these two lists, it can be judged that the view that 304L can be used instead of 304 is wrong. Whether it can be used is related to the use occasion, and in accordance with the regulations, we have no right to "substitute materials", only the original design department Only then can you have the right to carry out the work of "substituting materials". Please remember this.

One of our Shock absorber accessories are all use stainless steel material, and performance good.

All our CNC machining stainless steel part will be shipping with certificate of material.