The pump manufacture wants to use 316 SS for the wetted parts and claims verbally that this will not corrode (atleast not too much for the design life). Austenitic stainless steel 316L has been widely used in marine environment which containing sodium chloride solution (NaCl). Corrosion Resistance: In choosing between 316 and 316L stainless steels, the latter has a slight edge over the former. The molybdenum-bearing Alloys 316 and 317L stainless steel also provide resistance to a wide variety of other environments. An Austenitic Stainless Steel Containing Molybdenum Which is More Corrosion Resistant than the Conventional 304/304L Stainless Steel Alloy 316-316L 06/2014 www.SandmeyerSteel.com SANDMEYER STEEL COMPANY ONE SANDMEYER LANE PHILADELPHIA, PA 19116-3598 800-523-3663 +1-215-464-7100 FAX +1-215-677-1430 Providing Solutions, With Materials and Compared to 316ss, 316L steel has better resistance to pitting and crevice corrosionover its useful life. As a consequence it: Moderate Effect, not recommended for continuous use. B = Good. 304 stainless steel has an anti-corrosive property like normal stainless steel. Good resistant to pitting and crevice corrosion in warm chloride environments. At temperature as high as 120 F (49 C), Type 316 is resistant to concentrations of this acid up to 5 percent. Thanks to its outstanding capabilities, Type 316 . N/A = Information Not Available. Softening, loss of strength, swelling, may occur. The key difference is the addition of molybdenuman alloy which drastically enhances corrosion resistance, especially for more saline or chloride-exposed environments. Corrosion Resistance Table of Stainless Steel Nickel Monel Inconel The table below indicates the approximate corrosion resistance of selected corrosion resistant metals to a range of common chemicals. Stainless Steel Chemical Resistance Chart Chemicals A-B A = Excellent. The resistance of austenitic stainless steels to SCC is related to the nickel content of the steel. Stainless Steel 316 (S31600): Higher corrosion resistance than types . The key difference that makes them totally different is the addition of molybdenum, an alloy which drastically enhances corrosion resistance, particularly for more saline or chloride-uncovered . 316 Stainless Steel is commonly used for food processing equipment, and as surgical stainless steel. The two most common stainless steel grades are 304 and 316. The resultant composition of CS 316 gives the steel much increased corrosion resistance in many aggressive environments. C = Fair. Stainless steel 316Ti offers better resistance to intergranular corrosion. The very tough and ductile austenitic structure gives grade 316 excellent formability and fabrication characteristics. Type 316 (UNS 31600) is an austenitic chromium-nickel stainless steel alloy containing molybdenum. The key difference is the addition of molybdenum, an alloy which drastically enhances corrosion resistance, especially for more saline or chloride-exposed environments. Therefore, 316l stainless steel is a better choice for your project as it can withstand a higher rate of exposure to environmental factors, chemicals, and acid. N/A = Information Not Available. 304 vs 316 Stainless Steel - The Pros and Cons | Arthur Harris. Stainless Steel. 316 stainless is a general purpose workhorse stainless steel, but it is unsuited to chloride containing liquors. . Type 316 is known for its corrosion resistance to pitting and crevice corrosion in chloride environments. The molybdenum content increases corrosion resistance, enhances resistance to pitting in chloride ion solutions and augments strength at high temperatures. D = Severe Effect, not recommended for ANY use. The most susceptible austenitic grades have nickel contents in the range of 8 to 10 wt%. Type 316 contains around 2.5% Molybdenum whereas type 304 does not contain Molybdenum. Stainless steel floats The main difference between 304 vs. 316 stainless steel involves the 316 grade's much higher levels of molybdenum, which are typically 2-3 percent by weight and provide better corrosion resistance. SS316 Heat Resistance 316 SS has good oxidation resistance in intermittent use below 871 C and continuous use up to 927 C in air. The molybdenum content increases corrosion resistance, improves resistance to pitting in chloride ion solutions, and increases strength at high temperatures. Properties of this austenitic stainless steel grade are similar to those of type 304 . Figure 2: Cracking threshold for 304 and 316 alloys exposed to near neutral chloride-bearing waters. In addition to coastal areas, sea sprays, and salt in rain water, heavy exposure to chloride can also be present in many parts of the country that use de-icing salts on roadways. In conclusion, corrosion of 316 stainless steel in a chloride environment is a definite problem. This oxide layer forms when chromium in the alloy reacts with oxygen in ambient air. It is well demonstrated that corrosion resistance of 316 stainless steel in purified NaCl-MgCl 2 eutectic salt is excellent at high temperature. This is collated information from various sources but is of limited quality. (630) 833-0300 Order History Clear All Material Show Stainless Steel 316 Stainless Steel Shape System of Measurement Inch Metric Thickness 0.001" 0.002" 0.003" 0.004" 0.005" 0.006" 0.007" 0.008" 0.009" 0.01" 0.012" 0.014" 0.015" 0.016" 0.017" 0.02" 0.022" 0.024" 0.025" 0.027" 0.03" 0.031" 0.033" 0.036" 0.045" 0.048" 0.05" 0.06" 1/16" 0.063" 0.075" 304 and 316 stainless steel substrates are among the most commonly used grades of stainless steel materials in many industries. Moderate Effect, not recommended for continuous use. Max temp for this water is around 100 F but typically around 70 F. Difference between Duplex Steel & 316 Stainless Steel: Austenitic 304 and 316 stainless steels are thought of surgical or medical-grade stainless steels, they are the most commons stainless steels. Also known as surgical stainless steel, marine steel, 316S16 (as per the British Standard), SS 316 is an austenitic chromium-nickel alloy. The alloy has a tensile energy of 579 MPa (84 ksi) and a . Minor Effect, slight corrosion or discoloration. To address the widely held concern that ISO15156/NACE MR0175 limits for sour service cracking resistance of Type 316/316L stainless steel in oil & gas production environments were excessively conservative, a program of laboratory studies was undertaken testing parent materials in compliance with the ballot requirements of this standard. 316 Stainless Steel. 304 stainless steel does not. As part of the five families of stainless steel, 304 stainless steel and 316 stainless steel are austenitic grades that contain high levels of chromium and nickel. Chlorine and chloride are different forms of the same element but with vastly different effects on stainless steel. Softening, loss of strength, swelling, may occur. The presence of molybdenum makes 316 a good material for marine environments for the oil and gas industry. Masteel produces corrosion-resistant stainless steel grades such as grade 316, which is recommended for use in severe applications. However, 316L SS experiences localized corrosion as a result of passive film breakdown in aggressive corrosive environment. Corrosion resistance to potable water at ambient temperature range is up to 1000mg/L of chlorides. As an austenitic stainless steel alloy, it has qualities corresponding to excessive power, corrosion resistance, and high concentrations of chromium and nickel. The increased performance of this austenitic chromium-nickel stainless steel makes it better suited for environments rich in salt air and chloride. the addition increases corrosion resistance, particularly against chlorides and other industrial solvents.316 stainless steel has additional molybdenum that gives it resistance to chlorides and other processing chemicals. At temperatures under 100 F (38 C), this type has excellent resistance to higher concentrations. 316 stainless steel is known for its 2-3% molybdenum content. The cracking threshold of a 6Mo super austenitic stainless steel (UNS N08367) immersed in oxygen-bearing neutral . Cl2 (chlorine) is a very potent oxidizer (reason it kills bacteria) and therefore high levels of Chlorine may accelerate chloride corrosion of stainless steels. The two most common stainless steel grades are 304 and 316. Type 316 grade stainless steel is particularly effective in acidic environments. Molybdenum & Stainless Steel Sodium chloride (NaCl) in seawater actively attacks the iron (Fe) molecules in submerged alloys, causing pitting corrosion. The effects of chloride content, oxygen. The key difference between these two grades is the addition of 2~3% of molybdenum (Mo) to the 316 family of stainless steels. They are also widely used in handling hot organic and fatty acids. In other words, with its lower carbon content, 316L lasts longer in high-chloride environments. Next is the stainless steel important to 304.Compared with class 304, molybdenum has 316 better overall corrosion resistance, especially in the chloride environment with higher pitting and . Molybdenum is the reason that makes the metal stronger or gives resistance to corrosion and to beat elevated temperature. Intergranular . Type 316Ti alloy on the other hand, due to its Mo-content, will handle waters with up to about 2000 ppm chloride. 316 stainless steel contains molybdenum, but 304 doesn't. The molybdenum makes the steel more resistant to pitting and crevice corrosion in chloride-contaminated media . Chloride salts, such as NaCl, KCl, MgCl 2, and ZnCl 2, are abundant in nature and boil at higher temperature than 1400 C. . Stainless steel utilizes the principle of passivation, wherein metals become "passive" or unreactive to oxidation from corrosive compounds found in the atmosphere and process fluids. I am looking for any links or research someone might know of that can guarantee 316 SS for use in this concentration of chlorides. 316 stainless steel contains molybdenum. This work investigated the corrosion behavior of base metal 316L and SMA 316L weld metal by using Electrochemical Impedance . The most notable property of 316 stainless steel is its extreme resistance to corrosion, particularly corrosion from chloride sources, such as seawater and many industrial chemicals. Looking specifically at sulfuric acid, Type 316 is more protective. The austenitic grades of stainless steel are more prone to SCC, and their resistance to SCC depends on their nickel content. SAE 316 SS Also Known as A4 Stainless or 18/10 for its composition of 18% chromium and 10% nickel. While 316 comes in second in terms of quantities sold, it offers vastly superior corrosion resistance to chlorides and acids. Chloride is part of the salt in natural waters and even 304 can cope with a few hundred ppm at ambient temperatures and pH~7. Temperature Conversion Service tests are usually desirable as operating conditions and acid contaminants may significantly affect corrosion rate. . 316 stainless steel has a mid-range level of carbon and contains between 2% and 3% molybdenum, which increases resistance to corrosion, acidic elements, and high temperatures. 316 stainless steel also has good resistance to chloride attack, so it is commonly used in marine environments. The molybdenum gives 316 better overall corrosion resistant properties than Grade 304, notably higher resistance to pitting and narrow openings corrosion in chloride environments. 316 is also know as marine grade stainless steel due to its higher resistance to chloride corrosion compared to type 304.. 316L is an extra low carbon grade of 316, often found in stainless steel watches. . Stainless steel loses its resistance to corrosion when the chromium content drops below 10.5-11%. To minimize this prob-lem, low carbon stainless steel metal should be used in this environment as the encapsulation for RTD probes. 304 stainless is also cheaper in cost compared to 316, another reason for its popularity and widespread use. 304 and 304L, 321 SS may be used for "water applications" with up to 2 ppm chlorine, while 316 and 316L alloys may "take" up to 4 ppm. This addition increases corrosion resistance, improves resistance to pitting chloride ion solutions and provides increased strength at elevated temperatures. 316 is a member of the 18/8 chromium nickel family of austenitic stainless steels, with an addition of 2% molybdenum for improved corrosion resistance, particularly to localised corrosion in chloride containing environments. Uses for SS AISI 316. SS grade 316 is an Austenitic standard . 316 Stainless Steel Chemical Compatibility Chart ver 10-Jan-2020 industrialspe Key to General Chemical Resistance [all data based on 72 (22 C) unless noted] A = Excellent - No Effect C = Fair - Moderate Effect, not recommended B= Good - Minor Effect, slight corrosion or discoloration D = Severe Effect, not recommended for ANY use Because of high corrosion resistance, good mechanical strength, and low cost, 316L stainless steel (SS) is widely used in oil and gas industries [16]. Grade 316 is an improved version of CS 304, with the addition of molybdenum and a slightly higher nickel content. 316 is usually regarded as the standard "marine grade stainless steel", but it is not resistant to warm sea water. Chloride stress corrosion cracking (CLSCC) is one of the most common reasons why austenitic stainless steel pipework and vessels deteriorate in the chemical processing and petrochemical industries. Grade 316L, the low carbon version of 316 and has very high immunity from sensitization (grain boundary carbide precipitation). This makes it generally more corrosion resistant than the 304SS , and more expensive. 316 stainless steel can be used in coastal regions or areas where de-icing salts are frequently used because of its resistance to chloride. in fact "stainless" is a misnomer - all stainless steels are only corrosion resistant and their resistance is dependent on their working environment and the alloy used. SS316 steel is an austenitic chromium-nickel stainless steel that contains between 2 and 3% molybdenum. 316 Stainless steel has better corrosion properties due to its molybdenum content which improves its resistance to pitting in chloride ion solutions and makes it strong for higher temperatures. Both materials have excellent malleability, meaning they perform well in bending, stretching, deep drawing, and spinning. Temperature Conversion F = (1.8 x C) + 32 C Continue reading . D = Severe Effect, not recommended for ANY use. Type 316 is a popular chromium, nickel, molybdenum-bearing stainless steel grade. With a maximum carbon content of 0.03, 316L stainless steel can be used in applications where no annealing after welding and where maximum corrosion resistance is required. 316 / 316L Stainless Steel Tubing With the addition of molybdenum, grades 316 and 316L stainless steel were developed to offer improved corrosion resistance compared to alloy 304/L. EN 1.4401 grade 316 stainless steel (16% chromium, 10% nickel and 2% molybdenum) is the second most important austenitic Stainless Steel compared to 304. . The corrosion resistance of molybdenum-bearing 316L austenitic steel is particularly effective in chloride-ion environments. Its resistance to chloride attack means it is often . The melting range of 316 is 2,500 F - 2,550 F (1,371 C - 1,399 C), roughly 50 to 100 degrees Fahrenheit lower than the melting point of grade 304 stainless steel. This is particularly associated with crevices and rough surface finish. S tainless stee l 316 has good resistance to oxidation in intermittent service to 870C and in continuous service to 925C. The differences between stainless steel 316, 316L, 316H, 316Ti: (1) 316 stainless steel is austenitic chrome-nickel stainless steel containing molybdenum. Table 3. However, continuous use at 425-860C is not recommended if corrosion resistance in water is required. Chlorine is bleach and stainless steels can only tolerate exposure to a few ppm continuously. Type 316 stainless steel can be . The anti-corrosion properties that set 316 steel apart come from the inclusion of molybdenum in its composition. The effects of chloride content, oxygen content and solution pH were studied on test coupons with and without welds and on U-bend specimens. Type 304 is only resistant to up to 3% acid at room temperature while type 316 is resistant to up to 20% acid at temperatures of up to 50 C. 316 stainless steel has better corrosion resistance than 304 stainless steel. Superior Resistance to Chloride - Corrosive salts can be present in many areas of the country. 316 stainless steel is often referred to as a marine grade alloy due to its outstanding resistance to chloride corrosion. Stainless Steel Chemical Resistance Chart Chemicals F-L A = Excellent. Type 316 steel is an austenitic chromium-nickel stainless steel that contains between two and 3% molybdenum. (140F) and to pitting and crevice corrosion in warm chloride environments. This addition drastically enhances the corrosion and oxidation resistance of the alloy . The message. However, the inclusion of the 2% molybdenum in the SS 316 helps make the grade resistant to chlorine while improving its resistance to acid and alkalis. B = Good. 316 Stainless steel:This grade of stainless steel comes under the austenitic form of stainless steel. In order to provide matching properties with parent metal, filler metal SMA 316L is commonly produced with slightly over alloyed composition. 316L Stainless Steel Chemical Compatibility Chart ver 10-Jan-2020 industrials Key to General Chemical Resistance [all data based on 72 (22 C) unless noted] Explanation of Footnotes 1 - Satisfactory to 120 F (48 C) A = Excellent - No Effect C = Fair - Moderate Effect, not recommended In this instance 316L is recommended due to its resistance to carbide precipitation. C = Fair. Compared to 316, 316L stainless steel has a higher resistance to corrosion from chlorides and acids. The molybdenum component prevents chloride ions pitting the and crevassing the surface of the steel. This addition increases corrosion resistance, improves resistance to pitting chloride ion solutions and provide increased strength at elevated temperatures. Common stainless steels. SS316L is resistant to carbide precipitation in the temperature range of 425-870 C (800-1600 F), so normal welding can be performed without reducing corrosion resistance. This has the following impact: Chromium - Increases tensile strength, hardness, hardenability, toughness resistance to wear and abrasion, resistance to corrosion and scaling at elevated temperatures. 316 SS (Stainless Steel) is an austenitic form of stainless steel which contains 2 to 3 % of molybdenum. Type 316 steel is not magnetic, but may be weakly magnetic after cold working. This is why type 316 stainless steel has a better pitting resistance than type 304 stainless steel. Though it is often referred to as marine grade stainless steel, it is in fact not resistant to seawater. It is resistant to potable water containing up to approximately 1000mg/L chlorides at room temperature 20C . 304 stainless steel is the most versatile and widely used austenitic stainless steel in the world, due to its corrosion resistance. Austenitic grades with nickel contents in the range of 8 to 10 wt% (e.g., 304 /304L and 316/316L) are more prone to such attack due to SCC. Corrosion Resistant Stainless Steel from Masteel. reduce the resistance of Type 316Ti stainless steel to highly oxidizing environments including the nitric acid Though the stainless steel 304 alloy has a higher melting point, grade 316 has a better resistance to chemicals and chlorides (like salt) than grade 304 stainless steel. Evaluation was performed for pitting and crevice . Austenitic grades that have high nickel and molybdenum contents such as alloy 20 . 316 / 316L is commonly known as "marine grade stainless steel", although it is not resistant to warm sea water. How to Choose Between 316 or 316L Stainless Steel Heat Resistance It is called Chloride Stress Corrosion Cracking (CSCC) of austenitic stainless steels, and is one of the main factors to consider when evaluating the . It is particularly effective in acidic environments and in defensive against corrosion caused by the sulfuric, hydrochloric, acetic, formic . Grade 316 is a well-liked alloy of stainless steel with a melting range of 2,500 F - 2,550 F (1,371 C - 1,399 C). Along with the increased nickel content, 316SS also has an additional element 'Mo' (molybdenum) in its chemical makeup (2%-3%). Both steels are durable and provide excellent resistance to corrosion and rust. The resistance to localized corrosion of stainless steels in 20,000,100,000 and 200,000 ppm Cl-sodium chloride solutions was investigated at 90C. In all stainless steels, chromium and nickel are critical for corrosion resistance and ductility. In comparison, SS AISI 316 boasts better resistance to chloride-rich conditions than the typical SS 304 thanks to the molybdenum addition. It offers the standard corrosion resistance, formability, strength, and easy maintenance for which stainless is known. This reduces to about 500mg/L at 140F. The Benefits of 316 Stainless Steel Most stainless steel ordered around the world is Grade 304. The relative resistance of a stainless steel to chloride SCC is often quantified by the use of standard boiling salt solutions. This added molybdenum makes the metal more resistant to corrosion, pitting and improves its resistances at elevated temperatures as well as provides greater resistance to acids and localized corrosion caused by chloride ions. 316 stainless steel is commonly used in many industrial applications involving processing chemicals, as well as high-saline chloride. This is because it has more molybdenum and less carbon. Chlorine as a sterlising or sanitising agent When using chlorine as a steriliser or sanitiser in contact with 316 type stainless steel items, a maximum of 15-20 ppm, (mg/lt), 'free' chlorine is suggested, for maximum times of 24 hours, followed by a thorough chlorine free water flush. The addition of >10% chromium transforms steel into stainless steel, creating an adherent and invisible oxide layer that is chromium-rich. Therefore, standard grades such as 304/304L and 316/316L are very susceptible to this mode of attack. In many marine environments 316 does exhibit surface corrosion, usually visible as brown staining. Increasing amounts of chromium and molybdenum contents in stainless steel provide increasing resistance to reducing acids. The objectives of this work were: To draw conclusions and give recommendations for best practice in assessing susceptibility to . Minor Effect, slight corrosion or discoloration. The resistance to localized corrosion of stainless steels in 20,000,100,000 and 200,000 ppm Cl - sodium chloride solutions was investigated at 90C.