Stainless Steel，Selecting the Right Grade

Stainless steel is among the best corrosion resistance material out there. But that is not merely it; stainless steel has a lot of benefits including excellent formability, high strength-to-weight ratio, low maintenance, ability to recycle, etc.

How To Find The Right Stainless Steel Grade For Your Needs

Owing to its versatility, stainless steel has a wide range of application. Stainless steel comes in a lot of different grades, and we will help you pick out the best for the job.

Formability

If the application needs stainless steel with good formability, try not to use the martensitic category of stainless steel. Instead, you should opt for the austenitic grade (304 or ferritic grade (430) of stainless steel. Moreover, Martensitic stainless steel can get brittle and lacks adequate formability.

For Welding

Welding stainless steel is completely different from welding carbon steel as there are high chances of hot stress corrosion cracking, intergranular corrosion, etc. Austenitic group of stainless steel are among the most welded stainless steel. If you are welding, then it is recommended that you use 304L or 347 grade of austenitic stainless steel. While the grade 304L features lower carbon, 347 comes with niobium stabilizers, assisting in the protection of intergranular corrosion. You can also use ferritic stainless steel grade, including 439 or 439.

For Machinery

If your process requires stainless steel to be a machine, you have to be more specific about the grade of stainless steel you choose. While a majority of stainless steel can be machined, some are more complex than the others. You need to optimize the machining process to boost the efficiency of your work, along with using the right tool. Sulfur can be added to improve the machinability, which you can find in grade 303 stainless steel. Additionally grade 416 stainless steel tube is another good example of it.

The level of Corrosion Resistance

Stainless steel is known for its corrosion resistance properties. However, different grade of stainless steel offers a distinctive level of corrosion resistance. If you need maximum corrosion resistance, then you should opt for austenitic stainless steel as they contain the highest amount chromium. So you should opt for 304 grade of stainless steel. Ferritic stainless steel, on the other hand, is a more cost-efficient option than austenitic stainless steel as they have less concentration of nickel and chromium.

Heat Treatment

If the stainless steel is going through any heat treatment, you should be aware of how different grades might be affected by it. For austenitic and ferritic stainless steel are two non-hardenable grade of stainless steel when exposed to heat. Martensitic or precipitation hardened stainless steel is ideal for heat treatment.

Strength Requirement

Martensitic stainless steel grade such as 440C or precipitation hardened stainless steel grade 15-5 PH 17-4 PH are the best options when it comes to acquiring maximum strength. Considering the high nickel content, austenitic stainless steel also offers high toughness and ductility.

The right grade of stainless steel depends on the purpose you need it for. Above are some of the best choices for the grade based on unique purposes, so next time you will be able to make the right decision.

How to Pick the Right Stainless Steel Grade

Stainless steel is arguably one of the greatest inventions in human history. With millions of applications spanning across every major industry, the production of the metal alloy continues to rise globally. In 2019, worldwide steel production was approximated at 52.2 million metric tons, more than doubling from a decade before.

Stainless steel comes in a variety of grades, such as 302 stainless steel. With over 3500 grades to choose from, it can be challenging for fabricators to find the right grade. Here are five tips to guide you during the selection process.

1. Operating Environment

The metal alloy or combined metals are forged from a combination of steel and other metals such as chromium and nickel. Steel’s anti-corrosive properties and versatility make it vital in countless applications in industries such as construction, automobiles, food and beverage, medical, and chemical processing, to name a few.

You need to find a steel grade that will uphold the best in a given environment. Think about the conditions that the steel product will face. High temperatures, varying pH levels, stress, and corrosion may impact the functionality of your steel. Austenitic grades such as 302 stainless steel, 304, and 316 series retain their strength, corrosion resistance, and toughness properties on a broad temperature range.

2. Mechanical Qualities

Next, you may need to give importance to mechanical qualities, such as strength, ductility, and toughness. Strength refers to the stress that a metal can withstand before deforming or fracturing. Ductility relates to the ability of a metal to have its shape changed. Toughness is the ability to deform and absorb energy before a metal fracture.

Stainless steel contains 10-30% chromium that aids in corrosion prevention. Nickel addition in austenitic grades like 302 stainless provides the highest toughness and ductility. Martensitic steels, like grade 440C, provide the best strength.

3. Corrosion Resistance

While stainless steel gets a good rap for being corrosion resistant, it varies greatly among the different grades. Austenitic grades such as 316, 304, and 302 stainless steel are among the most sought after for corrosion resistance due to high levels of chromium. Ferritic steel grades and martensitic are more affordable but will have fewer percentages of nickel and chromium.

4. Formability

If the application of the stainless steel casts requires good formability, it would be wise to avoid martensitic grades. These grades often tend to be brittle and not formable. Austenitic grades such as 304 stainless steel or 302 stainless steel would be an excellent choice. Ferritic grades such as 430 can also work.

5. Material Cost and Availability

You may need to find out the common applications of the different grades of steel to help you choose the right one for your project. Alloy 302 stainless steel is commonly used in stamping and spinning. Ferritic grade 409 is majorly in automotive exhaust systems, while austenitic 316L is for chemical applications that require welding. Austenitic steel grades are usually the most expensive upfront. Carefully examine the cost, needs, and availability of the thin sheet metal before settling for one.

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