不锈钢(SS)有各种形状、尺寸和成分。它是一种由铁、镍和铬等几种不同元素组成的合金，与它的组成部分相比具有更好的耐腐蚀性能。不同的应用要求不同的材料性能。事实上，单单不锈钢就有几十种不同的等级，每一种都有独特的成分比例和应用效益。本文将重点介绍两种类型:17-4和316L不锈钢。
17-4 Stainless Steel
17-4 stainless steel, also known as SAE Type 630, is a common and exceptionally durable type of steel used in a diverse variety of industries and applications. The numbers “17-4” refer to its composition: ≈17% chromium and ≈4% nickel. It also can include between 3 and 5% copper. It is the most common material used in the production ofSetra’s variable capacitance transducers.Its durability and mechanical properties make 17-4 SS the ideal choice for transducers in both HVAC and general industrial applications.
316L Stainless Steel
316L stainless steel is defined by its low carbon content: no more than 0.03% carbon. In general, its composition is between 16-18% chromium and between 10-14% nickel (as well as trace amounts of manganese, silicon, phosphorus, sulfur and nitrogen). The number 316 refers to a reference number assigned bySAE International, a standards organization that serves the automotive and aerospace industries.
316L SS is favored in many industrial applications for its resistance to corrosion, especially when in prolonged contact with hydrogen. Hydrogen is used as a process medium across many different applications and can cause other materials to deteriorate over time — a process calledhydrogen embrittlement.
Hydrogen embrittlement can cause the process media to leak into the immediate environment and pose serious safety and contamination risks. 316L SS is resistant to hydrogen embrittlement, making it the standard wetted material used in pressure transducers, such as theSetra Model AXD, that use hydrogen and other corrosive gases as process media.
CLICK HEREto learn more about the importance of material compatibility between 17-4 and 316L stainless steel.
