904L Stainless Steel Balls 27.00mm 1 inch -1/16" Inch G100 G200 Mirror Polished Surface

27.00mm(1-1/16"), 904L High Precision Stainless Steel Metal Ball For Bearing

Introduction

Super austenitic stainless steel 904L (00Cr20Ni25Mo4.5Cu; UNS: N08904; EN: 1.4539) is a high-alloy austenitic stainless steel with low carbon content. It has good corrosion resistance in dilute sulfuric acid and is specially designed for corrosive conditions. Designed for harsh environments. It has high chromium content and sufficient nickel content. The addition of copper makes it highly resistant to acid, especially chloride crevice corrosion and stress corrosion cracking. It is not prone to corrosion spots and cracks, and it is resistant to spots. Corrosion ability is slightly better than other steel grades, has good good workability and weldability, and can be used for pressure vessels.

Grades and standards:

UNS N08904 (a standard jointly designed by the American Society of Motor Vehicle Engineers and the American Society for Testing and Materials in 1967), DIN1.4539 (German Standard), ASTM A240 (American Society for Testing and Materials Standard; the new standard classifies it as a stainless steel series, The original standard ASME SB-625 classified it as a nickel-based alloy series), SUS890L.
 

Metallographic structure of 904L stainless steel:
904L is a completely austenitic structure. Compared with austenitic stainless steel with high molybdenum content, 904L is not sensitive to the precipitation of ferrite and α phase.
 

Physical and mechanical properties:
Density: 8.0g/cm3. Tensile strength: σb≥520Mpa. Elongation: δ≥35%. Corrosion resistance of 904L stainless steel.

Application notes of 904L:

1.1 Welding performance
Like ordinary stainless steel, 90 4 L can be welded in various welding methods. The most commonly used welding method is manual arc welding or inert gas shielded welding. The electrode or wire metal is based on the composition of the base material and has a higher purity, and the content of molybdenum is higher than that of the base material. Generally, it is not necessary to preheat before welding, but in cold outdoor operation, in order to avoid condensation of water vapor, the joint or the adjacent area can be uniformly heated. Note that the local temperature should not exceed 100°C to avoid carbon accumulation and intergranular corrosion. It is advisable to use small heat input, continuous and fast welding rate when welding. Generally, heat treatment is not required after welding. If heat treatment is required, it must be heated to 110 0 ~ 1150 ℃ and then quickly cooled.

1.2 Machining performance
The machining characteristics of 90 4 L are similar to other austenitic stainless steels, and there is a tendency of sticking and work hardening during machining. Positive front angle cemented carbide tools must be used, and vulcanized and chlorinated oils are used as cutting coolants. The equipment and processes should be based on the premise of reducing work hardening. Avoid using slow cutting speed and feed rate during cutting.

904L application fields:

* Petroleum and petrochemical equipment, such as reactors in petrochemical equipment, etc.
* Sulfuric acid storage and transportation equipment, such as heat exchangers, etc.
* Power plant flue gas desulfurization device, the main parts used in the tower body of the absorption tower, flue, gate plate, internal parts, spray system, etc.
* Scrubber and fan in the organic acid treatment system.
* Sea water treatment equipment, sea water heat exchanger, paper industry equipment, sulfuric acid, nitric acid equipment, acid making, pharmaceutical industry and other chemical equipment, pressure vessels, food equipment.
* Pharmaceutical factories: centrifuges, reactors, etc.
* Plant food: soy sauce cans, cooking wine, salt cans, equipment and dressings.
* 904L is a matched steel grade for the strong corrosive medium of dilute sulfuric acid.

The minimum value of the mechanical properties of the alloy at room temperature:

Composition