There are many types of stainless steel quick couplings, which refer to alloy steels with a cr content greater than or equal to 13% and are not rusty in the atmosphere. There are austenitic stainless steel quick couplings, ferritic stainless steel quick couplings, martensitic stainless steel quick couplings and so on. Stainless steel quick couplings generally do not have magnetism, but they are not absolute. Austenitic ones have no magnetism, but ferrite ones have, but they are relatively weak. Different stainless steel quick couplings have different corrosion resistance and different corrosion resistance to different media.
The difference between carbon steel and stainless steel quick couplings is generally believed to be corrosion resistance first. However, in practical applications, stainless steel quick couplings have excellent various properties that cannot be replaced by other steel types. For example, some high-temperature stainless steel quick couplings, and the excellent surface characteristics of stainless steel quick couplings are widely used in decorative materials. The excellent mechanical properties of stainless steel quick couplings make it used in various manufacturing industries.
Ordinary steel is carbon steel, that is, iron-carbon alloy. According to the level of carbon content, it is divided into low-carbon steel (to be called wrought iron), medium-carbon steel and cast iron. Generally, those with a carbon content of less than 0.2% are called low-carbon steel, commonly known as wrought iron or pure iron; those with a content of 0.2-1.7% are called steel; those with a content of more than 1.7% are called pig iron.
1. The steel that contains more than 12.5% chromium in steel and has high resistance to corrosion by external media (acid, alkali salt) is called stainless steel quick joint. According to the structure of the steel, stainless steel quick couplings can be divided into martensitic, ferritic, austenitic, ferrite-austenitic, precipitation hardening stainless steel quick couplings, according to the national standard gb3280-92. There are 55 regulations.
In our daily life, there are austenitic stainless steel quick couplings (some people call it nickel stainless) and martensite stainless steel quick couplings (some people call it "stainless iron", but they are unscientific and easy to misunderstand. , Should be avoided) two categories. The typical grades of austenitic stainless steel quick couplings are 0cr18ni9, namely "304" and 1cr18ni9ti. Martensitic stainless steel quick joints, such as stainless steel quick joints for making knifes and scissors, etc. The main brands are 2cr13, 3cr13, 6cr13, 7cr17, etc.
2. Due to the difference in the composition of the two types of stainless steel quick joints, the microstructure of the metal inside is different.
3. Austenitic stainless steel quick joints are added with high chromium and nickel (chromium content is about 18%, ni is above 4%), the internal structure of the steel presents a state called austenite. This kind of tissue is not magnetic and cannot be attracted by magnets. Commonly used as decorative materials, such as stainless steel quick-connect pipes, towel racks, tableware, stoves, etc.
4. Martensitic stainless steel quick joints should be used to make stainless steel quick joints for knives and scissors. Because knives and scissors have the function of cutting objects, they must have sharpness, and to have sharpness, they must have a certain degree of hardness. This kind of stainless steel quick joints must undergo heat treatment to make the internal structure change, and increase the hardness before they can be used as scissors. However, the internal structure of this type of stainless steel quick joint is tempered martensite, which is magnetic and can be attracted by magnets. Therefore, we cannot simply use whether it is magnetic or not to explain whether it is a stainless steel quick joint material.
