Stainless Steel 317 was designed to be a higher strength alternative to the 316 grades. Composed of larger amounts of chromium, nickel and molybdenum, SS 317 also is more corrosion resistant compared to 316, and tougher than Type 304. This is the due to the high percentage of iron in its composition, which is much higher than many stainless steels. This combination of iron with the chromium-nickel-molybdenum content yields a strong, hardy alloy.
In terms of working capability, all common welding, hot working and cold working practices can be applied. 317 demonstrates good versatility. It will only work harden under cold working, which will also increase its strength. When heat treating this metal, temperatures should not drop below 1700°F as this is the threshold for response.
Stainless steel 317 is commonly found in the textile industry, where its strength and corrosion resistance can be utilized. Other applications include the manufacturing of chemical equipment and the machines used in pulping paper.
Stainless Steel 317L is the low-carbon derivative of SS 317. The metal maintains its high strength and strong corrosion resistance; however, the carbon content does have several effects. 317L has greater strength under welding; its products are stronger.
Like 317, stainless steel 317L does not respond or harden from heat treatments. When hot working, the metal should be heated ideally within the range of 2100-2300°F. Dropping below 1700°F will cause the metal to be unresponsive. For these reasons, 317L is effective in high temperature areas that experience high rates of chemical corrosion, creep, and stress-to-rupture.
317L is commonly utilized in chemical environments. It has shown itself to be effective in conditions where acids are present, such as acidic chloride. The metal is resistant to corrosion from such substances. As such, it is common to find 317L in equipment used in pulp and paper mills. The acidic environment requires a strength, corrosion resistant metal.
It is possible for grades 317 and 317L to become dually certified.