Mechanical Properties of Austenitic Stainless Steel S31660 1Cr18Ni12Mo2Ti

Mechanical Properties of Austenitic Stainless Steel 1Cr18Ni12Mo2Ti S31660

Introduction

Austenitic stainless steel 1Cr18Ni12Mo2Ti (S31660) is one of the most widely used high-performance stainless steels in the world. It has superb corrosion resistance and excellent mechanical properties, making it suitable for a variety of applications in industry and control products. S31660 is an austenitic modified ferritic stainless steel with an additional titanium alloy composition, offering a tailored combination of high temperature strength, resistance to stress corrosion cracking and pitting, hot hardness, and optimal formability. The chemical composition of S31660 and its mechanical properties, as well as its manufacturing processes, are critical in determining the performance of the stainless steel. This paper investigates the mechanical properties of 1Cr18Ni12Mo2Ti S31660 and explores the possible manufacturing techniques for this material.

Chemical Composition of 1Cr18Ni12Mo2Ti S31660

The chemical composition of 1Cr18Ni12Mo2Ti S31660 is outlined in Table 1. It contains a high chromium content (18-20 wt.%) and a nitrogen content (0.10-0.20 wt.%), which gives the steel its superior corrosion resistance, improving the pitting resistance of the steel significantly. The nickel and the molybdenum content also provide good resistance to corrosion and oxidation, making this alloy suitable for a variety of applications in chemical processing, piping systems, and other applications requiring high temperature strength and resistance to corrosive environments.

Table 1. Chemical composition of 1Cr18Ni12Mo2Ti S31660

Element Percentage Weight (%)

Carbon (C) 0.08

max

Manganese (Mn) 2

max

Nitrogen (N) 0.10 – 0.20

Phosphorus (P) 0.035

max

Sulfur (S) 0.030

max

Silicon (Si) 1

max

Chromium (Cr) 18 ~ 20

Nickel (Ni) 10 ~ 14

Molybdenum (Mo) 2 ~ 2.5

Titanium (Ti) 0.80 ~ 1.20

Mechanical Properties of 1Cr18Ni12Mo2Ti S31660

The mechanical properties of 1Cr18Ni12Mo2Ti S31660 are outlined in Table 2. This stainless steel has a very high mechanical strength, with an Ultimate Tensile Strength (UTS) of 775-890 MPa and a Yield Strength (YS) of 630-795 MPa. It also has good fatigue strength and excellent creep strength, making it suitable for high temperature and pressure applications such as valves and pumps.

Table 2. Mechanical Properties of 1Cr18Ni12Mo2Ti S31660

Properties Test Method Value

Ultimate Tensile Strength ASTM A564 775-890 MPa

Yield Strength ASTM A564 630-795 MPa

Elongation ASTM A564 20 - 25 %

Brinell Hardness ASTM A564 285 - 345

Fatigue Strength ASTM A564 660-890 MPa

Creep Strength ASTM A564 300-500 MPa

Thermal Properties

The thermal properties of 1Cr18Ni12Mo2Ti S31660 are outlined in Table 3. This stainless steel has a low thermal expansion coefficient, which makes it suitable for applications requiring high dimensional stability. It has a high thermal conductivity, which allows it to easily transfer heat across surfaces and components, improving efficiency. The thermal conductivity of 1Cr18Ni12Mo2Ti S31660 is 17.0 W/m-K at room temperature.

Table 3. Thermal Properties of 1Cr18Ni12Mo2Ti S31660

Properties Test Method Value

Specific Heat Capacity ASTM A564 0.491 J/g·K

Melting Point ASTM A564 1430 °C

Linear Thermal Expansion ASTM A564 15.8 x 10-6 /K

Thermal Conductivity ASTM A564 17.0 W/m·K

Manufacturing Process

1Cr18Ni12Mo2Ti S31660 can be produced by a variety of manufacturing processes, including hot-rolling, cold-rolling, forging, and casting. The manufacturing process chosen depends on the type of product being manufactured and the application for which it is being used. For example, hot-rolling is typically used to manufacture flat products, such as sheets and plates, while forging is typically used to produce components with complex shapes and higher strength requirements. Casting is often used to produce products with larger surfaces, such as valves and pumps.

Conclusions

In conclusion, 1Cr18Ni12Mo2Ti S31660 is a high performance stainless steel with excellent mechanical properties and superior corrosion resistance. It can be produced using a variety of manufacturing processes, such as hot-rolling, cold-rolling, forging, and casting, and its properties can be tailored according to the application. The mechanical properties of 1Cr18Ni12Mo2Ti S31660 make it suitable for a variety of applications in industry and control products.

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316LN (1Cr18Ni12Mo2Ti) stainless steel is a new type of austenitic stainless steel developed in the 80s. Compared with 316L special steel, 316LN steel has higher nitrogen content, so the yield strength of 316LN is higher, but its ductility and impact toughness also decrease accordingly.

In terms of mechanical properties, the tensile strength of 316LN stainless steel after solution treatment is ≥520MPa, the 0.2% yield strength is ≥200MPa, the elongation is ≥42%, the reduction of area is ≥50%, the impact work is >90J, and the hardness is ≤187HB. In addition, the annealing temperature of 316LN stainless steel is between 1080-1240℃, and the cooling speed is relatively slow.

316LN stainless steel has excellent corrosion resistance, especially intergranular corrosion resistance, and exhibits excellent stress corrosion resistance. Compared to ordinary austenitic stainless steels, it has better anti-chloride corrosion performance, so it can be safely used in seawater and other media containing chlorides.

In addition, 316LN stainless steel has the characteristics of good weldability and excellent machining performance. It has been widely used in petrochemical equipment, food production equipment, nuclear power and other sector.