What Is the Yield Strength of Stainless Steel?

The yield strength of stainless steel is defined as the property, and the amount of stress refers to the yield point at which the material starts to deform naturally and takes a plastic form. We can find out that an extremely allowable load can be sustained by a mechanical component with the help of yield strength.

The stress that will result in permanent deformation of 0.2% of the original dimension is known as yield strength. It is a point at which a material has gone beyond its elastic limit and cannot be stretched or compressed back to its original state when stress is removed. The yield strength values can be obtained by stress-strain diagram during the tensile testing method.

Yield strength is a very important property of a material in determining the suitability of a specific grade of stainless steel for your desired application. It is affected by the material’s manufacturing method, heat treatment, and chemical composition. In this article, we will discuss the yield strength of stainless steel grades, its measurement, and the factors affecting it.

Yield strength of 304 stainless steel

The 304 stainless steel is a well-known grade of stainless steel and is most widely used in many applications due to its excellent corrosion resistance, formability and high strength. The yield strength of grade 304stainless steel can be affected by heat treatment, manufacturing process and tempered condition of this alloy.

Usually, the yield strength of 304 stainless steel ranges from 205 to 290 MPa or 30,000 to 42,000 pounds per square inch (psi), depending upon the temper conditions of this grade. We can improve the yield strength of 304 stainless steel with the help of a heat treatment process and increase its resistance to deformation.

This grade of stainless steel is generally ideal for a wide range of applications, including those in the structural, automotive, and aerospace sectors, among others, due to its high yield strength.

What is the 316 stainless steel yield strength?

The austenitic stainless steel type 316 is widely utilized in various industries, including chemical processing, food and beverage production, pharmaceuticals, and medical equipment. This grade of stainless steel has more yield strength than grade 304.

The yield strength of 316 generally ranges from 205 MPa to 515 MPa depending upon the temper condition of this grade. For applications requiring high strength and endurance, such as pressure vessels, heat exchangers, and structural parts in the marine and aerospace sectors, 316 stainless steel’s high yield strength makes it the perfect material.

What is the yield strength of 301 stainless steel?

Grade 301 also belongs to the austenitic stainless steel family. It has 17% chromium and 7 % nickel in its composition, providing excellent ductility and strength when cold worked. Depending on the specific grade and the manufacturing process, different conditions of this grade have different yield strengths.

301-1/2 Hard, the most popular grade of stainless steel, has minimum yield strength of 75 Ksi or 515 MPa. This grade of stainless steel is frequently used in applications that require high strength, like washers, springs and clips. 301 Full Hard is a common grade of 301 stainless steel with minimum yield strength of 185 Ksi or 1276 MPa. This grade is utilized in highly demanding applications like automotive, medical, and aircraft parts.

It is important to remember that features like the heat treatment process, the material’s thickness, and the presence of additional alloying elements can all impact the yield strength of 301 stainless steel.

Factors affecting the yield strength of stainless steel

The yield strength of stainless steel can be affected by various factors, some of which are described below.

Strain rate

The loading rate can also impact the yield strength of stainless steel. Greater strain rates can result in stronger yields; however, lower strain rates can result in lower yield strength.

Heat treatment

The heat treatment process can significantly impact the yield strength of stainless steel. The strength of stainless steel can be decreased by annealing, which involves heating the metal to a specified temperature and then slowly cooling it. On the other hand, steel can be strengthened through cold working, which involves deforming the material at low temperatures.

Temperature

The yield strength of stainless steel can also be impacted by the temperature at which it is utilized. In general, stainless steel’s strength might be affected by higher temperatures.

Composition

The yield strength of this grade can be considerably impacted by its chemical composition. Chromium is a vital element of stainless steel, which boosts its durability and resistance to corrosion. Adding other elements, including nickel, molybdenum, and nitrogen may impact its strength.

Surface condition and temper conditions

The quality of its surface can also impact the yield strength of stainless steel. The material’s strength can be reduced, and its durability weakened by corrosion or other surface flaws.

Different temper conditions have different yield strengths. Half-hard and quarter-hard stainless steel has low yield strength than full-hard and spring-hard conditions.

The yield strength of different grades of stainless steel’s annealed condition is given in the following table.

How can we measure the yield strength of stainless steel?

The most frequent technique for determining yield strength is tensile testing. Stainless steel specimens are subjected to an increasingly higher load until they Undergo permanent deformation.

At each increment, the machine will record the load and elongation. Calculate the point at which the stainless steel starts to yield or when it starts to deform plastically. The point is called yield strength.

We can determine the yield strength of stainless steel by dividing the load by the specimen’s cross-sectional area. With the help of a caliper or another measuring tool, the cross-sectional area can be measured.

 Marking a stress-strain curve involves measuring the load and the resulting deformation. The stress is the actual force applied on the cross-sectional area of the specimen, while the strain is defined as the change in the length of the specimen / original length.

The yield strength of austenitic stainless steel grades is shown in the given table.