Features of the 316 Stainless Steel
1.Corrosion resistance: Because of exceptional corrosion resistance, the 316 stainless steel has wide applications in the chemical industry. It is also a derived kind of steel from the type 18-8 austenitic stainless steel, with a content of 2%-3% element Mo added. A lot of steels are derived from the 316 stainless steel, such as 316Ti with a small amount of Ti added, 316N with a small amount of N added, and 317L with the contents of Ni and Mo increased. The 316 stainless steel on the market is mostly manufactured base on American standards. Considering the cost, a steel factory normally reduces the content of Ni as much as possible to the lower limit.
The content of Ni for the 316 stainless steel is 10-14% according to the American standards and 12-15% according to the Japanese standards. When you compare them for the lower limit, there is a difference of 2% as to the content of Ni, which reflect a big difference between their prices. Therefore, when buying products made of the 316 stainless steel, pay some attention to its standards, ASTM or JIS. The content of Mo allows the 316 stainless steel to have exceptional pitting corrosion resistance and thus to be used safely in the environment with halide ions like Cl－. The 316 stainless steel is used mostly because of its chemical properties, so a steel factory has lower requirements for surface inspection (than 304). Attach more importance to the surface inspection if you have higher surface requirements.
2.Heat resistance: During intermittent use below 871°C (1600°F) or continuous use above 927°C (1700°F), the 316 stainless steel (06Cr17Ni12Mo2) presents good oxidation resistance. However, it is better not to subject the 316 stainless steel to continuous use in the range of 427°C-857°C (800°F-1575°F). When used continuously outside of the this temperature range, the 316 stainless steel presents good heat resistance. The the 316L stainless steel has better carbide precipitation resistance than the 316 stainless steel and can be used in the above temperature range.
3.Thermal treatment: In the temperature range of 850-1050 °C, carry out annealing, and then rapid annealing, and finally rapid cooling. Thermal treatment cannot be performed for hardening of the 316 stainless steel.
4.Welding: With good weldability, the 316 stainless steel can be welded with all standard welding methods. Based on the purpose, 316Cb, 316L or 309Cb stainless steel padding bars or welding rods can be used for welding. In order to acquire the best corrosion resistance, annealing needs to be performed for the welding cross section of the 316 stainless steel. The 316L stainless steel needs no annealing after welding.
Properties and purposes of the 316 stainless steel
With the content of Mo added, the 316L stainless steel features very good corrosion resistance, atmosphere corrosion resistance and high temperature resistance and can be used in harsh conditions. It also has excellent machining hardness (no magnetism) and high temperature strength. As an austenitic stainless steel, the 316L stainless steel cannot be reinforced by the thermal treatment. It also features good strength, plasticity, tenacity, cold formability and excellent low temperature performances. The 2% content of Mo added based on Cr18Ni8 gives the steel good reducibility medium resistance and pitting corrosion resistance as well as proper corrosion resistance in various organic acids, mineral acids, alkalies, salts, and seawater. It has much better corrosion resistance than 304 in a reducible acid medium and presents excellent corrosion resistance during pulping and papermaking. Besides, the 316 stainless steel has resistance against erosion from the ocean and the erosive industrial air. During intermittent use below 1600 degrees or continuous use above 1700 degrees, the 316 stainless steel presents good oxidation resistance. It is better not to subject the 316 stainless steel to continuous use in the range of 800 – 1575 degrees. When used continuously outside of the this temperature range, the 316 stainless steel presents good heat resistance. The the 316L stainless steel has better carbide precipitation resistance than the 316 stainless steel and can be used in the above temperature range. In the temperature range of 850-1050 degrees, carry out annealing, and then rapid annealing, and finally rapid cooling. Featuring high temperature resistance, easy machinability and high strength, the 316L stainless steel needs no annealing after welding.
Based on the above introduction, we can see that this 316 stainless steel component is very complicated for whether machining modes or machining steps, with a lot of machining processes. On the premise of the above conditions guaranteed, this 316 stainless steel component must be kept on a high level for its accuracy, which is very time and labor consuming. This is why most stainless steel products manufacturers would not like to do it. However, with the sense of responsibility for 20 years, Yijin Hardware deeply understands that there must be someone to do something for the water treatment for the sake of human beings, and Yijin Hardware would like to play such a role.