difference between 630 stainless steel strip and 631 stainless steel strip

Difference Between 630 Stainless Steel Strip And 631 Stainless Steel Strip

630 stainless steel strips and 631 stainless steel strips are made with stainless steel coils.

These two alloys are 95% the same in composition. There are some differences in properties.

Grade 630 stainless steel strips have 17% chromium and 4% nickel contents and are also known as UNS 17400 and 17-4 PH.

On the other hand, the grade 631 stainless steel strips have 17% chromium and 7% nickel contents and are also known as UNS 17700 and 17-7PH.

The 630 stainless steel strips are martensitic stainless steels that have undergone precipitation hardening to improve their mechanical characteristics.

After heat treatment, these strips reach exceptional levels of strength and hardness.

Grade 630 stainless steel strips have heat and corrosion resistance similar to grade 304 stainless steel strips.

The 631 stainless steel strips have outstanding features for strength, high hardness and elasticity, good resistance to corrosion, resistance to high temperatures, and resistance to deformation.

Strips made of 631 stainless steel offer useful property combinations that are exceptionally well-suited for aeronautical applications.

Let’s keep reading.

One of the most well-known and frequently employed precipitation hardening type of high strength stainless steel strips.

With copper addition, impact hardened with martensitic structure is called 17-4PH / 630 / 1.4542. High-strength qualities, such as hardness, are maintained while retaining a high level of corrosion resistance.

While maintaining reasonably excellent characteristics, 630 stainless steel strips can operate in the temperature range of -29 °C to 343 °C.

Apart from that, the materials of this grade have decent ductility and corrosion resistance.

630 stainless steel grade’s availability under solution-treated conditions, at which point they may be easily machined and age-hardened to achieve high strength, is one of its main advantages.

Cold-rolled strips are available in 17-4PH, 630 and 1.4542.

The 630 stainless steel strips are widely used for heavy-duty mechanical parts, bushings, rotor blades, couplings, screws, drive shafts, nuts, and measuring devices in the aerospace, marine, paper, energy, offshore, and food industries.

What is 631/17-7PH/1.4568 Stainless Steel Strip?

The 17-7PH/631/1.4568 stainless steel strips are among the age-hardened PH materials with the highest amounts of chromium and nickel at 17% and 7%, respectively.

Additionally, these stainless steel strips have high strength and exceptional corrosion resistance.

These 631 stainless steel alloy strips also have outstanding flat spring qualities at temperatures up to 600°F (316°C).

The edge of a 17-7 PH stainless steel strip can be made as a slit or round variety, depending on the manufacturing method.

The 631/17-7PH stainless steel strips are utilized in machine constructions and parts such as valve parts, containers, springs, spring washers, food knives, diaphragms, high and low-temperature parts, heat exchangers, unique fittings, and installations.

Strips, wires, sheets, and bars made of 631 stainless steel are used in the aerospace, chemical, petrochemical, energy, food, and cryogenic industries.

Grade 630 Stainless Steel Strip vs. Grade 631 Stainless Steel Strip Comparison

The 630 stainless steel strips and 631 stainless strips are slightly similar.

However, there are some differences in composition and properties.

630 Stainless Steel Strip

Chemical composition

The chemical composition of 630 stainless steel strips is given below
Chromium 15-17%
Nickel 3-5%
Manganese 1%
Silicon 1%
Phosphorus 0.040%
Sulfur 0.03%
Copper 3-5%
Carbon 0.07%
Niobium +Tantalum 0.15-0.45%

Mechanical properties

Mechanical properties of 630 stainless steel strip up to 100 mm diameter/ thickness.
Tensile strength: 1200MPa max
Yield strength: 1172MPa
Elongation A50: 10%
Hardness, Rockwell C:
40

Density

The density of 630 stainless strips is about 7.75 g/ cm³

631 Stainless Steel Strip

Chemical composition

Now discuss the chemical composition of grade 631 stainless steel strips
Chromium: 16-18%
Nickel: 6.5-7.75%
Manganese: 1%
Silicon: 1%
Phosphorus: 0.040%
Sulfur: 0.03%
Aluminum: 0.75-1.5%
Carbon: 0.090%

Mechanical properties

The mechanical properties of grade 631 stainless steel strips are given below.
Tensile strength: 1275MPa
Yield strength: 1030MPa
Elongation A50: 6%
Hardness, Rockwell C
41

Density

The density of 631 stainless strips is about 7.80 g/ cm³

What are the Grade 630 Stainless Steel Strips and Grade 631 Stainless Steel Strips Applications?

The 630 stainless steel strips are used in components for valves, bolts, and gears, Dies for molding plastic, Boat propeller shafts and high-strength pump shafts, and Elements of an engine.

In general, in situations where high strength or hardness is required, with some degree of corrosion resistance, the majority of uses are for precipitation-hardening 630 stainless steel strips. These strips are used in the aerospace and other high-tech industries because of their high strength. Some other important applications consist of the following:

Transfer of power High-quality engine components such as gears, valves, stronger shafts, steam turbine blades, and molding dies are also available.

The 631 stainless steel strip has excellent welding performance, strength, and hardness. Washers and springs are the main applications for stainless steel strips of grade 631/17-7. It is employed in those applications when great strength and corrosion resistance are required. Due to its minimal thermal distortion, it is also used in complicated parts.

The aerospace, petrochemical, chemical, and petrochemical sectors, as well as the energy, food, and cryogenic industries, all use stainless steel 631strips. Due to its low distortion during heat treatment, it is also used in complicated parts.

Which one between Grade 630 Stainless Steel Strip and Grade 631 Stainless Steel Strip is better?

Both 630 and 631 stainless steel strips are widely used in many applications and are very popular among customers.

The grade 631 stainless steel strip is better than 630 stainless steel due to extra Nickel contents and the addition of aluminum content in its composition.

The additional nickel content can increase the corrosion resistance and strength of 631 stainless steel strips.

The tensile and yield strength of 631 stainless steel strips is more than 630 stainless steel strips.

Conclusion

These two stainless steel strips have their importance in the industry.

The 630 and 631 stainless steel strips have excellent corrosion resistance, hardness, strength, and stability at high temperatures.

Due to excellent properties, these grades of stainless steel strips are in demand these days.

In case you have any question, feel free to contact HZW team. Here HZW will help you in all your stainless steel strips solutions.

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