المبيعات@hdcmfg.com
+86 150 5221 8226
+86 150 5221 8226

321 Stainless Steel​: Is It What You Need?

ملخص المواصفات

Quick Summary: 321 Stainless Steel

  • ما هو؟ An austenitic stainless steel stabilized with titanium for high-temperature and welding applications.
  • Key advantage: Better resistance to intergranular corrosion after welding compared to 304.
  • Heat performance: Maintains strength and stability under repeated or sustained high-temperature exposure.
  • Fabrication: Easy to form and weld; moderate machinability typical of austenitic stainless steels.
  • الاستخدامات النموذجية: Heat exchangers, exhaust systems, furnace parts, chemical and aerospace components.
آخر تحديث: 3 فبراير 2026

✅ تم التحقق من المحتوى التقني بواسطة مهندسي HDC

جدول المحتويات

321 stainless steel, also widely known in the industry as ER312, is one of those stainless steel types you’ll often hear across different industries. But, do you know what it is exactly? Do you know what 321 stainless steel is, where they’re used, and how people choose to use them?

If you don’t and you want to know more about it, then you’re in the perfect page. Our article for today will solely be focused in making sure you understand 321 stainless steel better than anyone else!

By the end of this article, you will know 321 stainless steel by heart!

What is 321 Stainless Steel Grade?

321 stainless steel 1مصدر: Smiths Advanced Metals

In the easiest way to describe it, 321 stainless steel is an الفولاذ المقاوم للصدأ الأوستنيتي made for applications that involve heat and welding. It contains chromium and nickel, with added titanium to help the material stay stable when exposed to high temperatures.

321 stainless steel is easy to form and weld and stays tough even at very low temperatures. You can’t harden it through heat treatment and it’s naturally non-magnetic.

اقرأ المزيد: إتقان الدقة باستخدام آلات CNC للفولاذ المقاوم للصدأ

321 Stainless Steel Composition and Properties

321 stainless steel 2
مصدر: Angang Steel

One of the most important things to know about these alloys would be its properties. Like many alloys, 321 stainless steel has its own fair share of advantages and benefits, making it easy to determine if it’s a good fit or not.

القوة والمتانة

321 stainless steel offers solid strength for most industrial uses, especially “heat” type situations. It holds its mechanical properties better than other typical grades when exposed to higher temperatures, helping prevent early material damage.

المقاومة الكيميائية

This grade handles many organic and inorganic chemicals well at moderate temperatures. It’s commonly used in environments where exposure to acids or reactive substances is expected, as long as conditions are controlled and not overly aggressive.

مقاومة التآكل

Typically, 321 performs much like 304; it stands out after welding or heat exposure. Thanks to the titanium content, corrosion is greatly reduced making it more reliable in applications that stay within higher temperature ranges.

مقاومة درجة الحرارة

321 stainless steel is built for heat; we’ll leave it at that. It performs in its best in intermittent service up to around 900°C and non-stop processing close to 925°C. Therefore, it’s a strong option for parts that face repeated heating and cooling cycles.

قابلية اللحام

Welding 321 stainless steel is pretty straightforward. The titanium in its chemical makeup helps prevent carbide buildup during welding, lowering the risk of corrosion in the heat-affected zone. In most cases, you wouldn’t need post-weld heat treatments.

قابلية التصنيع

Like most austenitic stainless steels, 321 can be more challenging to machine than carbon steel. Still, with proper tooling, speeds, and cooling, you can well enough manufacture and use it for most fabrication and custom part requirements.

التطبيقات

Because of its heat stability and weld performance, 321 stainless steel is widely used in heat exchangers, exhaust systems, furnace parts, chemical processing equipment, and aerospace components where high temperatures are part of daily operation.

Also Read: الفولاذ المقاوم للصدأ 303 مقابل 304: هل هما نفس الشيء؟

Stainless Steel 321 vs. 304

321 فولاذ مقاوم للصدأ 3مصدر: KongFang Metal

Stainless steel 321 and 304 are both austenitic stainless steels used in many everyday and industrial applications. At a glance, they look and behave similarly. However, they’re made for different conditions and situations, especially when heat or welding is involved. So, here’s a breakdown of how they’re different:

ميزة304 الفولاذ المقاوم للصدأ321 الفولاذ المقاوم للصدأ
نوع الفولاذ المقاوم للصدأالفولاذ المقاوم للصدأ الأوستنيتيAustenitic stainless steel (titanium stabilized)
التركيب الكيميائيChromium, nickelChromium, nickel, titanium
مقاومة الحرارةGood for general useBetter for sustained or repeated high heat
Weld PerformanceGood, but may need low-carbon fillerExcellent stability after welding
Strength at Room TemperatureSameSame
Strength at High TemperatureDrops faster with heat exposureMaintains strength better over time
التطبيقاتFood equipment, tanks, trim, pipingHeat exchangers, exhausts, aerospace parts
التكلفة والتوافرLower cost, widely availableHigher cost, slightly less common

Overall, the difference between 321 and 304 all boils down to how the material will be used over time, not just how it performs during installation.

If the application stays at normal temperatures and cost matters, 304 is often the more practical choice. When welding is involved and the part will see repeated heat exposure, 321 offers added peace of mind by reducing long-term corrosion risks.

321 Stainless Steel Equivalent

321 stainless steel 4مصدر: Metal Strip Solutions

Now that we know that 312 is an alloy that’s just based off of 304, we can therefore say that it’s equivalent to EN 1.4541, AISI 321, and UNS S32100.

If we’re talking about alternative grades, the following have been deemed the best and fittest:

  • Stainless Steel Grade 304 H
  • 347
  • Grade 304 L

Will Stainless Steel Rust?

Contrary to popular belief, just because it’s stainless steel doesn’t mean it can’t rust. Although stainless steel has high levels of corrosion resistance, it will, eventually rust under specific situations and circumstances. After all, it’s called “stainless” and not “stain-free.”

321 Stainless Steel Suppliers: Why HDC’s 321s are the Most Trusted

Many people, especially business owners understand that there’s nothing better than feedback, product quality, and speed in the steel industry. And we at HDC possess all those characteristics, all with flying colors.

Organizations and companies from all around the world trust us with what they need. Whether they need the typical stainless steel, titanium steel, copper, or even plastic, or if they need CNC machining and metal fabrication services, our team will be your best bet.

HDC’s expertise, mastery, and overall dedication will be the best business you will ever experience. Reach out to us and get a free quotation!

جدول المحتويات

اكتشف المزيد مع منشورات مدونتنا.

المشاركات الاخيرة

عرض سعر فوري مجاني!

احصل على عرض الأسعار الآن!

انتقل إلى الأعلى