The reason why stainless steel is magnetic is that most stainless steels contain martensite, austenite or iron. Martensite or iron elements will show magnetism, so some stainless steels will be magnetic. Austenite does not show magnetism, which is why some stainless steels show magnetism, while others do not.
#1 Which Types Of Stainless Steel Are Not Magnetic
And Which Types Of Stainless Steel Are Magnetic?
Martensitic stainless steel is magnetic, such as 2Cr13, 3Cr13, 4Cr14. Austenitic stainless steel is non-magnetic, such as 304, 316, etc.
#2 Is Stainless Steel Magnetic?
Stainless steel is magnetic.
The magnetism of a material is determined by whether the molecular arrangement is regular and the isotropy of the electron spin, which is the physical property of the material; while the corrosion resistance of the material is determined by the chemical composition of the material, which is the chemical property of the material. It is irrelevant whether the material is magnetic or not.
Generally speaking, austenitic stainless steel (represented by 304) is non-magnetic, but it may also have weak magnetism; while ferrite (mainly 430, 409L, 439 and 445NF, etc.) Representative) are generally magnetic.
#3 Is Stainless Steel Material Magnetic?
Yes
Stainless steel is a high-alloy steel material that contains a variety of alloying elements. According to different structures, stainless steel can be divided into austenitic, ferritic, martensitic, duplex and precipitation hardening systems.
Austenitic stainless steel is commonly used in the market, commonly known as 304, 304 is the representative steel grade of austenitic stainless steel. Austenitic stainless steel has excellent processability, weldability and corrosion resistance, accounting for about 60% of the world’s stainless steel consumption, and is of great economic value and use value. This stainless steel is non-magnetic. The representative steel grade of austenitic stainless steel is SUS304 (18Cr-8Ni-0.05C). SUS304 is also the most widely used stainless steel. The crystal structure is FCC (Face Centered Cubic), and the elongation is about 60% due to the generation of processing-induced martensite.
In daily life environment, it has sufficient corrosion resistance, but in order to further improve corrosion resistance, Mo is often added, and the biggest disadvantage is that stress corrosion cracking is relatively easy to occur. By increasing or decreasing the Ni content, the formation of processing-induced martensite can be controlled, and there are also steel grades such as SUS301 (17Cr-7Ni) that combine high strength and high toughness. In order to suppress intergranular corrosion at welded parts and reduce the C content to about 0.02%, L-shaped steel grades such as SUS304L and SUS316L have been developed. In addition, in recent years, the rise in the price of Ni raw materials has increased the cost. Therefore, the use of 200-series SUS201 (17Cr-4.5Ni-6.5Mn-0.2N) in which Mn is substituted for Ni, and the development of resource-saving stainless steel such as high-corrosion-resistant iron-based SUS have been carried out. This 200 series is also austenitic stainless steel and is also non-magnetic.
The other type of stainless steel is ferritic stainless steel, the representative ferritic stainless steel is SUS430 (16Cr-0.05C), which is a magnetic stainless steel, sometimes called “stainless iron”. Although it is magnetic, it does not mean it will rust. In order to improve corrosion resistance, workability and weldability, several steel grades of ferritic stainless steel have been developed. This type of steel basically does not contain Ni, so the price is relatively cheap, and it is widely used as ordinary stainless steel. The Cr content of industrially produced stainless steel is 11%-30%. SUS430 has a phase (ferrite phase) and phase (austenite phase) dual-phase structure in the high temperature region of the hot rolling process. In the cold rolling annealing process, heat treatment in the single-phase region results in a ferrite single-phase structure. It can also be high-Cr and low-C, there is no high-temperature phase, and it is a single-phase structure in the entire temperature range. The crystal structure is BCC, and the elongation is about 30%. The r value that is important for deep drawability is high. In order to improve workability, low C and N (high purity) and addition of Ti and Nb (stabilization) elements are carried out. Addition of Ti and Nb is also effective for improving weldability. Ferritic stainless steel is mostly used in construction, and the most common ones are handrails, escalators, railings, etc., which attract people’s attention. There are also such stainless steels marked with “304”, that is “Li Gui” stainless steel.
Martensitic, duplex, and precipitation hardening stainless steels may be slightly magnetic, and those with more ferrite in the structure are more magnetic.
#4 What Kind Of Stainless Steel Needs To Be Magnetic And Has Good Performance In All Aspects?
There are two types of stainless steel, austenite and martensite (ferrite). Generally, austenite (such as sus304, etc.) has no magnetic field or weak magnetic field. Martensite is magnetic. Almost all household stainless steel kitchen knives are magnetic, with high hardness and acid and alkali resistance, such as 430, 420 or 410. If you need slightly high magnetic stainless steel, you can choose 430.
for reference only. I have a lot of exposure to austenite.
#5 What Type Of Stainless Steel Is A Magnetic Stainless Steel Plate
1.Models With Magnetic Stainless Steel
Martensite or ferrite type: such as 430, 420, 410, etc. are magnetic.
2.The Types Of Stainless Steel
There are many kinds of stainless steel, which can be divided into several categories according to the organizational structure at room temperature:
- Austenitic type: such as 304, 321, 316, 310, etc. are non-magnetic or weakly magnetic.
- Martensite or ferrite type: such as 430, 420, 410, etc. are magnetic.
3.The Application Of Magnetic Stainless Steel
- Model 420-“cutting tool grade” martensitic steel, the earliest stainless steel similar to Brinell high chromium steel. It is also used for surgical knives and can be made very shiny.
- Model 430-ferritic stainless steel, for decoration, such as for car accessories. Good formability, but poor temperature resistance and corrosion resistance.
- Model 440-high-strength cutting tool steel, with slightly higher carbon content, higher yield strength can be obtained after proper heat treatment, and the hardness can reach 58HRC, which belongs to the hardest stainless steel. The most common application example is “razor blades”.
#6 What Material Stainless Steel Has The Highest Magnetic Permeability?
Ferritic stainless steel has the best magnetic conductivity, and there are ferritic stainless steels in the 400 series, such as 409, 430, 443, 444, 439, and 436. Carbon steel, ferritic and martensitic stainless steels are magnetic, and austenitic stainless steels are nonmagnetic.
There are various grades of stainless steel, and the application scope and physical and chemical properties of various grades are also very different. It is best to choose the right one. Stainless steel is divided into austenitic stainless steel, martensitic stainless steel and duplex stainless steel from the metallographic structure. Austenitic stainless steel is non-magnetic stainless steel, and martensitic and duplex stainless steel are magnetic.
Magnetic conduction and anti-rust are required. For home use, martensitic stainless steel is recommended, such as 410 (about 13% chromium) and 430 (about 17% chromium). Among them, 430 has higher chromium content and better anti-rust effect than 410. Same as magnetic. Duplex stainless steel is mainly used in the chemical industry, the price is relatively high, and it is not suitable for civilian use.