Characteristics Of Different Media And Description Of Suitable Materials

Nitric Acid (HNO3)

General Characteristics: It is an oxidizing medium. Concentrated HNO3 typically operates at temperatures below 40°C. Elements such as chromium (Cr) and silicon (Si) are resistant to oxidation, making stainless steel and other materials containing Cr and Si ideal for resisting corrosion from concentrated HNO3.
High silicon cast iron (STSi15R): Suitable for all temperatures below 93% concentration.
High chromium cast iron (Cr28): Suitable for all temperatures below 80% concentration.
Stainless steel (SUS304, SUS316, SUS316L): Suitable for all temperatures below 80% concentration.
S-05 steel (0Cr13Ni7Si4): Suitable for all temperatures below 98% concentration.
Commercially pure titanium (TA1, TA2): Suitable for all temperatures below the boiling point (except for fuming).
Commercially pure aluminum (Al): Suitable for all temperatures at room temperature (for use in containers only).
CD-4MCu age-hardened alloy: Suitable for all temperatures below the boiling point.
Due to their excellent corrosion resistance, materials such as Inconel, Hastelloy C, gold, and tantalum are also suitable.

Sulfuric Acid (H2SO4)

General Characteristics: The boiling point increases with the concentration. For example, at a concentration of 5%, the boiling point is 101°C; at 50% concentration, it is 124°C; and at 98% concentration, it is 332°C. Below 75% concentration, it exhibits reducing properties (or neutral), and above 75%, it exhibits oxidizing properties.
Stainless Steel (SUS316, SUS316L): Below 40°C, around 20% concentration. 
904 Steel (SUS904, SUS904L): Suitable for temperatures between 40~60°C, 20~75% concentration; below 60% concentration at 80°C.  
High Silicon Cast Iron (STSi15R): Various concentrations between room temperature and 90°C.
Pure Lead, Hard Lead: Various temperatures at room temperature.
S-05 Steel (0Cr13Ni7Si4): Concentrated sulfuric acid below 90°C, high-temperature concentrated sulfuric acid (120~150°C).
Ordinary Carbon Steel: Concentrated sulfuric acid above 70% at room temperature.
Cast Iron: Concentrated sulfuric acid at room temperature.
Monel, Nickel Metal, Inconel: Medium temperature and medium concentration sulfuric acid.
Titanium Molybdenum Alloy (Ti-32Mo): Below boiling point, 60% sulfuric acid; below 50°C, 98% sulfuric acid.
Hastelloy B, D: Below 100°C, 75% sulfuric acid.
Hastelloy C: Various temperatures around 100°C.
Nickel Cast Iron (STNiCr202): 60~90% sulfuric acid at room temperature.

Hydrochloric Acid (HCl)

General Characteristics: It is a reductive medium with the highest temperature at a concentration of 36-37%. Boiling point: at a concentration of 20%, it is 110°C; between 20-36% concentration, it is 50°C; therefore, the maximum temperature for hydrochloric acid is 50°C.
Tantalum (Ta): It is the most ideal corrosion-resistant material for hydrochloric acid, but it is expensive and commonly used in precision measuring devices.
Hastelloy B: Suitable for hydrochloric acid at temperatures ≤ 50°C and concentrations up to 36%.
Titanium-Molybdenum Alloy (Ti-32Mo): Suitable for all temperatures and concentrations.
Nickel-Molybdenum Alloy (Chlorimet, 0Ni62Mo32Fe3): Suitable for all temperatures and concentrations.
Commercial Pure Titanium (TA1, TA2): Suitable for hydrochloric acid at room temperature and concentrations below 10%.
ZXSNM(L) Alloy (00Ni70Mo28Fe2): Suitable for hydrochloric acid at a temperature of 50°C and a concentration of 36%.

Phosphoric Acid (H3PO4)

The concentration of phosphoric acid is typically between 30-40%, with a temperature range of 80-90°C. Phosphoric acid often contains impurities such as H2SO4, F- ions, Cl- ions, and silicate.
Stainless Steel (SUS316, SUS316L): Suitable for boiling point phosphoric acid with a concentration below 85%.
Durimet 20 (Alloy 20): Corrosion and wear-resistant alloy for temperatures below the boiling point and concentrations below 85%.   
CD-4Mcu: Age-hardened alloy, corrosion and wear-resistant.
High Silicon Cast Iron (STSi15R), High Chromium Cast Iron (Cr28): Suitable for various concentrations of nitric acid below the boiling point.
904, 904L: Suitable for various concentrations of nitric acid below the boiling point.
Inconel 825: Suitable for various concentrations of nitric acid below the boiling point.

Hydrofluoric Acid (HF)

General Characteristics: Hydrofluoric acid is highly toxic. High-silicon cast iron, ceramics, and glass are generally resistant to most acids, but hydrofluoric acid can corrode them.
Magnesium (Mg): It is an ideal corrosion-resistant material for hydrofluoric acid and is typically used for containers.
Titanium: Suitable for concentrations of 60-100% at room temperature; the corrosion rate increases with concentrations below 60%.
Monel Alloy: It is an outstanding material resistant to hydrofluoric acid, capable of withstanding all temperatures and concentrations, including boiling points.
Silver (Ag): Boiling hydrofluoric acid is commonly used in measuring devices.

Sodium Hydroxide (NaOH)

General Characteristics: The corrosiveness of sodium hydroxide increases with temperature.
SUS304, SUS304L, SUS316, SUS316L: Concentration 42%, room temperature to 100°C.
Nickel Cast Iron (STNiCr202): Concentration below 40%, temperature below 100°C.
Inconel 804, 825: Concentration (NaOH+NaCl) up to 42% can reach 150°C.
Pure Nickel: Concentration (NaOH+NaCl) up to 42% can reach 150°C.
Monel Alloy: Suitable for high-temperature, high-concentration sodium hydroxide solutions.

Sodium carbonate (Na2CO3)

The mother liquor of soda ash contains 20-26% NaCl, 78% Cl2, and 2-5% CO2, with temperature variations ranging from 32 to 70 degrees Celsius.
High silicon cast iron: Suitable for soda ash with a temperature of 32 to 70 degrees Celsius and a concentration of 20-26%.
Industrial pure titanium: Several major soda ash plants in China currently use titanium pumps made of titanium for mother liquor and other media.

Petrochemical, pharmaceutical, and food industries

Petroleum: 0Cr13, 1Cr13, 1Cr17.
Petrochemical: 1Cr18Ni9 (304), 1Cr18Ni12Mo2Ti (SUS316).
Formic Acid: 904, 904L.
Acetic Acid: Titanium (Ti), 316L.
Pharmaceutical: High silicon cast iron, SUS316, SUS316L.
Food: 1Cr18Ni9, 0Cr13, 1Cr13."