There are several kinds of stainless steel 304

There are several kinds of stainless steel 304

304 stainless steel is a good corrosion resistance of austenitic stainless steel, with strong oxidation resistance, not easy to rust. Used in decoration, kitchenware, electrical appliances, sanitary ware, industrial systems and more industries. 304 is a brand of stainless steel, but the material is divided into several kinds.

First, element content

The most important elements in 304 are Ni and Cr, but they are not limited to these two elements. Specific requirements are specified by product standards. Industry common judgment situation that as long as the Ni content is greater than 8%, Cr content is greater than 18%, it can be considered 304 stainless steel.

This is why the industry will call this type of stainless steel 18/8 stainless steel reason. In fact, the relevant product standards for stainless steel 304 has very clear provisions.

To determine whether a material is 304 stainless steel, must meet the requirements of each element in the product standard, as long as there is a does not meet, can not be called 304 stainless steel. However, the Ni element in its composition is very important, which directly determines the corrosion resistance of 304 material and its value.

2. Source of raw materials

In addition to material element content, it can also be divided according to the source of production of raw materials. It can be divided into two kinds: Dachang wood and calender material. Let's take a look at the differences between them.

1. Dachang positive material: It is cold-rolled stainless steel 304 produced by cold rolling of hot rolled material in the steel mill. The surface color is uniform without dark stripes and there will be no roll marks.

2. Calender material: Generally, private steel mills will calender cold rolled material into thinner cold rolled products, calender material is customized according to customer needs, and sometimes uneven thickness phenomenon, such as calender steel strip will appear thick in the middle and thin on both sides.

Due to the flexible operation of the calendering plant can be freely pressed according to customer requirements in line with the width and thickness of product production, such as positive stainless steel thickness is generally 1 word tail, such as 0.51mm, then only have 0.5mm; The calender is generally only 0.5mm, or in 0.49mm, thinner in 0.45mm and so on. The calender can reduce the waste generated in the production of stainless steel products and save the cost and materials.

Iii. Mode of production

Stainless steel 304 production mode has refining furnace and intermediate frequency furnace, the same brand respectively from different production mode, its performance are not the same.

1. refining charge: is made of ore and other materials with fine furnace coal refining, harmful raw material control is ideal, soft material, good polishing, smooth weld, the key is strong corrosion resistance, deep processing, good technology, bending pipe and welding and other deep processing is convenient.

2. medium frequency charge: belongs to waste metal smelting, both material and production process are poor, the composition control is not good grasp, the environmental damage is also very serious. In addition, the polishing effect is poor, the hardness is difficult to deep processing, and the important thing is that the performance is unstable and the corrosion resistance is poor. Intermediate frequency furnace is unstable and easy to rust, refining furnace material is stable and not easy to rust.

How many kinds of rust steel 304? From the element content can be divided into two standards, one is the American standard, the other is the Japanese standard. From the source of raw materials can be divided into two kinds, one is Dachang material, the other is private rolling material. From the production mode can also be divided into 2, one is the ore refining charge, the other is the waste metal furnace smelting medium frequency charge.