309/309س مقابل. 310/310S في درجات حرارة عالية

مقاومة الأكسدة من 309/309S مقابل. 310/310S في درجات حرارة عالية

Oxidation and الفولاذ المقاوم للصدأ

Under most conditions, metal alloys react with their environment. The most common reaction is oxidation, where metals combine with oxygen to form oxides.

In stainless steel, الكروم 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.

	يكتب 309 (UNSS30900)	Type 309S (نحن S30908)	Type 309H (نحن S30909)	Type 309Si (من 1.4828)	يكتب 310 (نحن S31000)	Type 310S (نحن S31008)	Type 310H (نحن S31009)	Type 310Si (من 1.4841)
ج	0.2	0.08	0.04 دقيقة 0.10 الأعلى	0.2	0.25	0.08	0.04 دقيقة 0.10 الأعلى	0.2
ن	—	—	—	0.11	—	—	—	0.11
من	2	2	2	2	2	2	2	2
ص	0.045	0.045	0.045	0.045	0.045	0.045	0.045	0.045
س	0.03	0.03	0.03	0.015	0.03	0.03	0.03	0.015
SI	0.75	0.75	0.75	1.50 دقيقة 2.50 الأعلى	1.5	1.5	0.75	1.50 دقيقة 2.50 الأعلى
كر	22.00 دقيقة 24.00 الأعلى	22.00 دقيقة 24.00 الأعلى	22.00 دقيقة 24.00 الأعلى	19.00 دقيقة 21.00 الأعلى	24.00 دقيقة 26.00 الأعلى	24.00 دقيقة 26.00 الأعلى	24.00 دقيقة 26.00 الأعلى	24.00 دقيقة 26.00 الأعلى
في	12.00 دقيقة 15.00 الأعلى	12.00 دقيقة 15.00 الأعلى	12.00 دقيقة 15.00 الأعلى	11.00دقيقة 13.00 الأعلى	19.00 دقيقة 22.00 الأعلى	19.00 دقيقة 22.00 الأعلى	19.00 دقيقة 22.00 الأعلى	19.00 دقيقة 22.00 الأعلى
الحديد	توازن	توازن	توازن	توازن	توازن	توازن	توازن	توازن

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 التخميل process seen in corrosion at lower temperatures.

Alloy Composition and Oxidation Resistance

ال محتوى الكروم in stainless steel plays a key role in high-temperature oxidation resistance.

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

309/309س مقابل. 310/310س

كلاهما كان لدينا 309 and ATI 310 نكون 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.

ملخص

في ملخص:

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