Views:2 Author:Site Editor Publish Time: 2020-09-04 Origin:Site
Precision CNC stainless steel machining parts are becoming the first choice in many industries due to their good physical properties.Stainless steel is one of the most popular industrial alloys in many machining projects due to its excellent physical properties. Although stainless steel is particularly popular in the fields of medical, automotive, aerospace, healthcare, and consumer electronics, its following advantages make stainless steel parts and products a viable choice for many industries and applications. The best and fastest way to manufacture stainless steel parts is CNC machining, which has a very wide range of machining. In this article we will discuss some characteristics of stainless steel machining parts.
The following knowledge points are listed below:
What are stainless steel machining parts
Types of stainless steel machining parts
Grades of stainless steel machining parts
We know that steel is an alloy of iron and carbon, with a maximum carbon content of 2.1%. Stainless steel is a group of steels that resist corrosion by adding alloying elements.
The term stainless steel is used to describe a family of approximately 200 steel alloys with outstanding heat and corrosion resistance. The carbon content is between 0.03% and 1.2%.
It is characterized by high chromium content. Stainless steel contains at least 10.5% of chromium, which can improve its corrosion resistance and strength.
The chromium in the alloy will produce a passive oxide layer when exposed to the air. This layer plays a protective role against further corrosion and basically prevents the alloy from rusting. This mechanism allows a long-term stain-free appearance under normal working conditions.
According to the environment that stainless steel can withstand, there are many grades and surface treatments to choose from. According to the microstructure, it can be divided into four categories.
(1) Austenitic stainless steel
Austenitic stainless steel has austenite as the main structure. Austenite is a solid solution of iron and carbon, which is formed when the critical temperature is 723°C. This series of stainless steels exhibit high toughness and impressive high temperature resistance.
70% of stainless steel is austenitic. It contains at least 16% chromium and 6% nickel.
The austenite stabilizer is an element added to promote the formation of austenite microstructure. This stainless steel is a non-magnetic metal and cannot be hardened by heat treatment. The corrosion resistance can be adjusted according to the use environment.
(2) Ferritic stainless steel
Ferritic steel usually only has chromium as an alloying element. The chromium content ranges from 10.5 to 18%. They have general corrosion resistance and poor manufacturing characteristics. The heat treatment method also cannot help harden the metal.
They generally have better engineering capabilities than austenitic grades. Unlike austenitic grades, they are magnetic. They also have good resistance to stress corrosion, thereby reducing the wear of corrosive materials.
(3) Duplex stainless steel
Duplex is a mixture of austenitic and ferritic stainless steel. Therefore, it has two-component properties. It has the characteristics of high chromium and low nickel. Duplex stainless steel has high tensile strength and good weldability, and has unique advantages.
It shows good resistance to stress corrosion, but not as good as the ferrite grade. It is stronger than ferrite grade, but lower than austenitic grade.
(4) Martensitic stainless steel
This stainless steel has high carbon content and low chromium content. Like ferrite, it is magnetic. Compared with other brands, its weldability is poor, but its hardenability is higher, and its performance can be improved by heat treatment.
Compared with austenitic and ferritic grades with the same chromium and alloy content, martensitic stainless steel has lower corrosion resistance.
(5) Precipitation hardening stainless steel
This subunit provides a combination of austenite and martensite properties. Hardening is achieved by adding one or more elements such as aluminum, molybdenum, niobium, titanium and copper.
High tensile strength can be developed through heat treatment. It contains chromium and nickel as alloying elements. These grades are used for high-speed applications such as turbine blades..
There are hundreds of grades of stainless steel on the market today. Choosing the right options for your application is very important because their properties can be very different from each other.The stainless steel industry still uses the American Iron and Steel Institute (AISI) stainless steel naming system. The numbering system uses three digits beginning with 2, 3, or 4.
(1) 200 series
This series is used for austenitic grades containing manganese. The nickel content of these chromium-manganese steels is very low (less than 5%).
The 200 series is used for:
l washing machine
l Catering equipment
l auto industry
l Halo equipment, etc.
(2) 300 series
This series is used to name austenitic stainless steel with carbon, nickel, and molybdenum as alloying elements. The addition of molybdenum improves the corrosion resistance in acidic environments, and the addition of nickel improves the ductility.
AISI 304 and 316 are the most common grades in this series. AISI 304 is often called 18/8 steel because it contains 18% chromium and 8% nickel
Stainless steel food container
Use stainless steel containers to hold hot food
Applications of 300 series stainless steel include:
Food and beverage industry
Structure in critical environment
(3) 400 series
Ferrite and martensite alloys form this series of stainless steels. These grades can be used for heat treatment. Has good strength and high wear resistance. But the corrosion resistance is lower than the 300 series.
Applications of the 400 series include:
Gas turbine components, etc.