What’s DSS?

DSS, the abbreviation of Duplex stainless steel, is a classification of stainless steels composed of two steel with the center one composed of either austenitize or ferric. These are also known as duplex steels since their chemical structure features two distinct phases, both of which are usually represented by martensite respectively. These steels are very useful in applications requiring extreme toughness since the two phases can be applied together at high temperatures and pressures. The duplex stainless steel is able to obtain sufficient hardness in both its austenitic and martensite phases due to the presence of significant amounts of residual austenite. The commonly used DSS grades are S31803, S32750 and SS32550.

The duplex stainless steel grades

Type	UNS	Sweden	German	France	Japan
Low alloy	UN23（SAF2304）	SS232（SAF2304）	W.Nr.1.4362	UR35N	DP11
Medium alloy	UNS S31500 UNS S31803	SS2376(3RE60) SS2377(SAF2205)	W.Nr.1.4417 W.Nr.1.4462	UR45N	DP1 DP8
High alloy	UNS S32900 UNS S31260	SS2324(10RE51)	W.Nr.1.4460 W.Nr.1.4501		329J1 329J2L
Super duplex	UNS S32750 UNS S32550	SS2328(SAF2507)	W.Nr.1.4410 W.Nr.1.4507	UR47N+ UR52N+

 

Apart from the alloy itself, another important factor that contributes to its corrosion resistance is the nickel content. Nickel is commonly found in higher percentages in most alloys, which makes it an extremely useful component. In comparison to nickel, which is often used in high-performance alloys for its electrical conductivity and ability to form good-quality alloys, nickel is not as frequently used in making high-quality duplex stainless steel. One of the most interesting aspects of nickel alloys is its corrosion resistance ability, which makes it the best alternative for high-performance materials. When mixed with the steel, nickel produces a more stable alloy, which can increase the alloy’s wear-ability and mechanical strength.

Another significant property of this alloy is its high resistance to thermal expansion. It exhibits a high level of thermal expansion resistance despite the expansion resistance ability of austenitic stainless steels, due to its superior mechanical properties. This property gives it an excellent corrosion protection capability, especially during the tempering/stain removal cycle. The excellent corrosion resistance feature of duplex stainless steel enables it to stand up against a wide range of chemicals. It also has high levels of resistance towards oil, grease and other liquids with a high viscosity level.

Apart from the above features, duplex stainless steel is also popular because of its high strength and durability. Its high strength rating of up to 300Kg is made possible through its ability to make use of two-directional mandrel rolls. It is comprised of a hard carbon fiber rolled into strips that are interlaced on both sides and formed into a bar with a mandrel. A further feature that makes it an excellent alloy is that its surface is completely smooth with no ridges.

One of the most important factors that contribute to the durability of duplex stainless steels is their low rate of pitting corrosion resistance. These steels exhibit a low rate of formation of crystalline grains inside the hot alloy. They can be used to build both large and small structures in different industries. Due to their resistance to crystalline grains, they are highly valued by the construction industry.

The mechanical properties of duplex stainless steel offer a number of benefits that make them an excellent choice for a wide range of applications. These properties allow these steels to be used for a variety of applications including precision engineering component building, heat exchangers and sheet metal fabrication. Some other important properties of this type of alloy include high heat tolerance, low density and excellent corrosion resistance. They also offer a number of mechanical properties that contribute to the overall properties of the alloy. These include extreme hardness, toughness, chemical resistance and creep resistance.