Vacuum industry often involves 201 stainless steel, 304 stainless steel, such as the professional nouns, what is 201, 304 stainless steel.
This we must first know what is stainless steel, stainless steel is resistant to so-called weak corrosive medium such as air, steam, water and acid, alkali, salt and other chemical etching medium corrosion of the steel, is that by joining nickel, molybdenum, titanium, niobium, copper, nitrogen and other elements of the alloy.
304 stainless steel is a kind of common stainless steel materials, corrosion prevention is better than 200 series stainless steel materials.
High resistance to high temperature also is better, can to to - 1000
304 stainless steel has good corrosion and corrosion resistance and good resistance to intergranular corrosion.
For oxidizing acid, obtained in the experiment, the concentration of 65% or less under the boiling temperature of nitric acid, 304 stainless steel has a strong corrosion resistance.
To most organic and inorganic acid and alkali solution with good corrosion resistance ability.
According to the composition can be divided into Cr (
The 400 series)
, Cr, Ni,
The 300 series)
The 200 series)
And precipitation hardening (
The 600 series)
The 200 series -
Manganese austenitic stainless steel 300 series -
Nickel austenitic stainless steel 301 -
Good ductility, used for forming products.
Also can rapid hardening by mechanical processing.
Abrasion resistance and fatigue strength is better than that of 304 stainless steel.
Corrosion resistance with 304, due to the carbon intensity of relatively high and better.
By adding a small amount of sulfur and phosphorus from 304 are more likely to machining.
The 18/8 stainless steel.
GB brand of 0 cr18ni9.
American iron and steel institute international stainless steel mark method is to mark all kinds of standard level in the three figures wrought stainless steel.
Including: (1) stainless steel austenite size designation in 200 and 300 series of figures.
(2) the ferrite and martensite in shape with 400 series stainless steel digital representation.
For example, some relatively common austenitic stainless steel is 201, 304, 316 and 310.
(3) ferritic stainless steel in 430 and 446 for tags, martensitic stainless steel in 410, 420 and 440 c for tags, bipolar (
Austenitic - ferrite)
(4), precipitation hardening stainless steel stainless steel and iron content less than 50% of the high alloy is usually USES the name of the patent or trademark name.
A standard classification and grading of tensile strength of sigma b (
Conditions of 520 or higher, yield strength sigma 0.
205 or higher, elongation delta (5
40 or higher, reduction of area bits (
60 or higher, hardness: 187 hb or less;
200 hv or less after we understand these parameters of stainless steel, should be about the vacuum cup main material for us to understand somewhat, stainless steel material with poor corrosion resistance, acid-proof alkaline, etc is very weak.
Simply, it is vacuum cup main material has good and bad.
Reason is very simple, good vacuum cup must use stainless materials, and a good stainless steel will increase the cost.
In a lot of small factory, for example, they have no brand, no market, no innovation, no scale, how in the fierce competition in the market drank cup pot, only to cut corners, churning out.
So a lot of small factory 201 inferior steel such as abuse, and even some pusher made of stainless iron thermos flask.
Were it not for professionals, just from the appearance it's hard to judge a thermos flask material, making it illegal manufacturer are overrepresented, final consumers.