309/309С против. 310/310S при высоких температурах

Устойчивость к окислению 309/309 с.. 310/310S при высоких температурах

Oxidation and Нержавеющая сталь

Under most conditions, Металлические сплавы реагируют со своей средой. The most common reaction is окисление, where metals combine with oxygen to form oxides.

In stainless steel, хром helps resist oxidation. A thin, stable chromium oxide layer (Cr₂O₃), called chromia, is formed on the surface. This layer grows slowly and adheres well to the metal, preventing faster-forming oxides from developing.

	Тип 309 (UNSS30900)	Type 309S (НАС S30908)	Type 309H (НАС S30909)	Type 309Si (ОТ 1.4828)	Тип 310 (НАС С31000)	Type 310S (НАС S31008)	Type 310H (НАС S31009)	Type 310Si (ОТ 1.4841)
С	0.2	0.08	0.04 min 0.10 max	0.2	0.25	0.08	0.04 min 0.10 max	0.2
Н	—	—	—	0.11	—	—	—	0.11
Мин.	2	2	2	2	2	2	2	2
П	0.045	0.045	0.045	0.045	0.045	0.045	0.045	0.045
С	0.03	0.03	0.03	0.015	0.03	0.03	0.03	0.015
И	0.75	0.75	0.75	1.50 min 2.50 max	1.5	1.5	0.75	1.50 min 2.50 max
Кр	22.00 min 24.00 max	22.00 min 24.00 max	22.00 min 24.00 max	19.00 min 21.00 max	24.00 min 26.00 max	24.00 min 26.00 max	24.00 min 26.00 max	24.00 min 26.00 max
В	12.00 min 15.00 max	12.00 min 15.00 max	12.00 min 15.00 max	11.00min 13.00 max	19.00 min 22.00 max	19.00 min 22.00 max	19.00 min 22.00 max	19.00 min 22.00 max
Фе	Баланс	Баланс	Баланс	Баланс	Баланс	Баланс	Баланс	Баланс

How Protection Works

Once a thick and stable chromium oxide layer is formed, it blocks further oxidation. As the layer grows thicker, oxidation slows down. This is because oxygen and metal ions must travel farther through the oxide layer.

This behavior is called protective scale formation. It is similar to the пассивация process seen in corrosion at lower temperatures.

Alloy Composition and Oxidation Resistance

The содержание хрома in stainless steel plays a key role in high-temperature oxidation resistance.

Alloys with at least 20% хром are usually considered heat-resistant.
Replacing iron with nickel can also improve high-temperature performance.

309/309С против. 310/310С

Оба ATI 309 и АТИ 310 являются highly alloyed austenitic stainless steels. Because of their composition, they offer excellent resistance to oxidation, especially at elevated temperatures.

How Oxidation Is Measured

The resistance to oxidation is often measured by tracking weight gain after exposure to high heat.

When a metal oxidizes, it absorbs oxygen and becomes heavier.
More weight gain usually means more oxidation and lower resistance.
Less weight gain suggests better protection and higher resistance.

Краткое содержание

В итоге:

309/309S and 310/310S form protective chromium oxide layers.
Higher chromium and nickel levels improve oxidation resistance.
310/310С, having more alloying elements, typically perform better in extreme heat.
Weight change testing is used to compare their oxidation performance over time.