The first is the difference in material content: 304 is the most common general stainless steel material on the market. Generally, the chromium content is 18 chromium and the nickel content is 8 nickel. In terms of chemical composition, 304D only contains 2.8 nickel, but 7 manganese, so strictly speaking, 304D is not a 304 material, although its chromium content reaches 18.
Although the chromium content of 304D is greater than 18, its nickel content is only 2.8. We know that the normal nickel content of 304d must be greater than 8.
Not only that, its copper content is still very high, and its manganese content is as high as above 7, which can't be related to 304 in a strict sense.
The insiders believe that it may be more appropriate to define it as D series. Moreover, D 1 1 already exists, so it may not be too much for you to specify D7 and D9. But you can't think that just because you have 18 chromes, you can add something with a suffix of 304, which is a bit excessive.
You know, 304 has a national standard, and the names cannot be confused at will. I am particularly worried that you will have such a steel idea from now on.
Followed by the price, the price of 304D stainless steel is about 3000 yuan cheaper than that of 304 stainless steel.
304D tax-included price 1 1400 (cold rolled plate 1 1700, thick plate 1 1900), the price difference is 3600.
Finally, performance. Due to the different contents of various elements in 304D and 304 stainless steel, the corrosion resistance of 304D is much worse than that of 304 stainless steel. So be sure to keep your eyes open when buying, and don't choose inappropriate stainless steel because of the price problem.
In fact, 304D stainless steel is an economical corrosion-resistant stainless steel independently developed by Qingshan, which is intended to replace 304 stainless steel. Its main advantage lies in improving the strength and hardness of stainless steel on the basis of ensuring certain corrosion resistance of stainless steel, and at the same time reducing the cost to the greatest extent, so the price advantage of 304D is also obvious.
Knowledge expansion:
304 stainless steel (industry nickname: 18/8 stainless steel) is a common stainless steel material with a density of 7.93 g/cm3 and high temperature resistance of 800℃. In order to maintain the inherent corrosion resistance of stainless steel, steel must contain more than 18% chromium and more than 8% nickel.
It has the characteristics of good processability and high toughness, and is widely used in industry, furniture decoration industry, food and medical industry, as well as making equipment and parts with good comprehensive performance (corrosion resistance and formability).
For 304 stainless steel, Ni element in its composition is very important, which directly determines the corrosion resistance and value of 304 stainless steel.
The most important elements in 304 are Ni and Cr, but they are not limited to these two elements. Specific requirements are stipulated by product standards. It is generally judged in the industry that as long as the Ni content is more than 8% and the Cr content is more than 18%, it can be considered as 304 stainless steel. This is why this kind of stainless steel is called 18/8 stainless steel in the industry. In fact, the relevant product standards have very clear regulations on 304, and these product standards have some differences for different shapes of stainless steel. The following are some common product standards and tests.
If you want to determine whether a material is 304 stainless steel, you must meet the requirements of every element in the product standard. As long as one does not meet the requirements, it cannot be called 304 stainless steel.