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The difference and application of stainless steel 430, 304, 316

Stainless steel 430, 304,316 are the material of valve body, valve stem/shaft, or valve disc/plate.

lug type butterfly valve body

lug type butterfly valve body

430 ferritic stainless steel containing more than 12% chromium can prevent oxidation caused by natural factors. It is called stainless steel. It belongs to 430 ferritic stainless steel. It has low thermal expansion rate, excellent formability and oxidation resistance. The code name in JIS is 430, so it is also called 430 stainless steel.

Application of 430 ferritic stainless steel: 430 stainless steel (16Cr) is often used to make household appliances, heat-resistant appliances, burners, home appliances, class 2 tableware, kitchen sinks, exterior decoration materials, bolts, nuts, CD rods, screens .

The difference between 430 stainless steel and 304, 316 austenitic stainless steel: 430 stainless steel and 304, 316 austenitic stainless steel are identified by spectral analysis and chemical element analysis. Both 304 and 316 are austenitic stainless steels. 316 is made of 304 stainless steel with molybdenum added. Therefore, 316 stainless steel has much better seawater and rust resistance than 304.
The difference between 304, 316 and 430 lies in the rust resistance. In addition to chromium, 304 and 316 also contain elements such as nickel and molybdenum, and are non-magnetic. Therefore, the rust resistance of 304/316 austenitic stainless steel is better than 430 stainless steel is much better and the price is much higher. To

Can the 430 stainless steel magnet hold it? 304 and 316 are not magnetic and cannot be attracted by magnets. Generally, it does not generate heat in a high-voltage electromagnetic environment, so it is used more. Martensitic and 430 ferritic stainless steel, precipitation hardening stainless steel are magnetic, and magnets can attract them.

Will 430 stainless steel rust? 430 stainless steel cannot resist the oxidation caused by chemicals in the air. Because there are more and more acidic chemicals in the air, 430 stainless steel will still be oxidized (rusted) due to unnatural factors after being used for a period of time.

Which is better, 430 stainless steel or 304? 304 austenitic stainless steel has excellent corrosion resistance and no magnetism. Relatively speaking, austenitic stainless steel 304 is better than 430 ferritic stainless steel.

How expensive is 430 stainless steel compared to 304? Generally speaking, austenitic stainless steel 304 is twice as expensive as 430 stainless steel.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

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Valve material and valve standards-(2)-body stem bonnet material

Selection of valve material:
There are many materials for manufacturing valve parts, including various types of ferrous and non-ferrous metals and their alloys, and various non-metallic materials. The materials for manufacturing valve parts are selected

16 U-type-flange-butterfly-vlave-body

16 U-type-flange-butterfly-vlave-body

according to the following factors:
1. The pressure, temperature and characteristics of the working medium.
2. The force of the part and its function in the valve structure.
3. Have better manufacturability.
4. If the above conditions are met, there must be a lower cost.

Section one: the material of the valve body, bonnet and valve plate
1. Gray cast iron: Gray cast iron is suitable for water, steam, air, gas, oil and other media with a nominal pressure of PN≤1.0MPa and a temperature of -10°C–200°C. The commonly used grades of gray cast iron are: HT200, HT250, HT300, HT500.

2.. Malleable cast iron: suitable for water, steam, air and oil media with a nominal pressure of PN≤2.5Mpa and a temperature of -30-300°C. Commonly used grades are: KTH300-06, KTH330-08, KTH350-10.

3. Nodular cast iron: suitable for water, steam, air and oil with PN≤4.0Mpa and temperature of -30-350°C. Commonly used grades are: QT400-15, QT450-10, QT500-7.

4. Carbon steel (WCA, WCB, WCC): Suitable for nominal pressure PN≤32MPa, suitable for medium and high pressure valves with operating temperature between -29°C and +425°C. Among them, 16Mn and 30Mn work at -29-595°C, and are often used to replace ASTM A105. Commonly used grades are WC1, WCB, ZG25 and high-quality steel 20, 25, 30 and low-alloy structural steel 16Mn.

5. Low temperature carbon steel (LCB): suitable for ethylene, propylene, liquid natural gas, liquid nitrogen and other media with nominal pressure PN≤6.4MPa and temperature ≥-196°C. Commonly used grades are ZG1Cr18Ni9, 0Cr18Ni9, 1Cr18Ni9Ti, ZG0Cr18Ni9.

6. Alloy steel (WC6, WC9), suitable for high temperature and high pressure valves with non-corrosive medium working temperature between -29-595°C; WC5, WC9 are suitable for working temperature between -29-659°C High temperature and high pressure valves for corrosive media.

7. Austenitic stainless steel, suitable for valves with corrosive media with working temperature between -196-600°C.
Eight. Monel alloy: mainly suitable for valves with hydrofluoric medium.
nine. Cast copper alloy: Mainly suitable for valves for oxygen pipelines whose operating temperature is between -29 and 595°C

Fig.1-1 Commonly used valve body material:

valve body material standard temp PN/Mpa medium
Grey cast Iron -15/200 ≤1.6 water,gas
Black Heart Malleable Cast Iron -15/300 ≤2.5 water, seawater, gas, Ammonia
ductile cast iron -30/350 ≤4.0 water,seawater,gas,air,steam
carbon steel (WCA,WCB,WCC) ASTM A216 -29/425 ≤32 non-corrosive water, oil, gas
Low temp carbon steel (LCB,LCC) ASTM A352 -46/345 ≤32 low temp application
Alloy(WC6,WC9,C5,C12) ASTM A217 -29/595 -29/650 High pressure non-corrosive corrosive medium
Austenitic stainless steel ASTM A351 -196/600 corrosive medium
Monel alloy ASTM A494 400 Hydrofluoric acid medium
Hastelloy ASTM A494 649 Strong corrosive medium such as dilute sulfuric acid
Titanium alloy Various strong corrosive media
Cast copper alloy -273/200 Oxygen, sea water
Plastic, Ceramic -60 ≤1.6 corrosive medium

 

Name material standard temp range °C application
WCB carbon steel ASTM A216 -29/425 non-corrosive water, oil and gas
LCB low temp carbon steel ASTM A352 -46/345 low temp applicaion
LC3 3.5% nickel steel ASTM A352 -101/340 low temp applicaion
WC6 1.25% chromium,         0.5% molybdenum ASTM A217 -30/593 non-corrosive water, oil and gas
WC9 2.25% chromium
C5 5% chromium,0.5% molybdenum ASTM A217 -30/649 light or non-corrosive application
C12 9% chromium 1% molybdenum
CA15(4) 12% chromium ASTM A217 704 corrosive application
CA6NM(4) 12% chromium ASTM A487 -30/482 corrosive application
CF8M stainless steel 316 ASTM A351 -268/649 when <425, need C=0.04% info corrosive,ultra low/high temp with no corrosive application
CF8C stainless steel 347 ASTM A351 -268/649 when <425, need C=0.04% info high temp, corrosive application
CF8 stainless steel 304 ASTM A351 -268/649 when <425, need C=0.04% info corrosive,ultra low/high temp with no corrosive application
CF3 stainless steel 304L ASTM A351 425 corrosive or non-corrosive
CF3M stainless steel 316L ASTM A351 454 corrosive or non-corrosive
CN7M alloy ASTM A351 425 Good resistance to hot sulfuric acid corrosion
M35-1 monel ASTM A494 400 Weldable grade, good resistance to common organic acid and salt water corrosion, resistance to most alkaline solutions
N7M Hastelloy B ASTM A494 649 Suitable for treating various concentrations and temperatures of hydrofluoric acid, with good resistance to corrosion by sulfuric acid and phosphoric acid
CW6M Hastelloy C ASTM A494 649 Very good resistance to strong oxidation, resistance to phosphoric acid, sulfurous acid and sulfuric acid at high temperatures
CY40 Inconel alloy ASTM A494 Resistant to strong corrosive fluids at high temperatures

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

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