One Question per Day in Applied Chemistry 8-14

316L is mainly used for highly corrosive media such as nicotinic acid, while 304 is used for ordinary chemical media

1. The main difference in chemical composition between 316L and 304 is that 316L contains Mo. Molybdenum is added to austenitic stainless steels to improve their thermal strength and creep strength, as well as to enhance their resistance to pitting and intergranular corrosion. Mo can passivate the steel surface in both reducing and strongly oxidizing salt solutions, thereby improving the steel’s corrosion resistance and preventing pitting in chloride solutions. Adding Mo can improve resistance to reducing acids and pitting corrosion, while reducing carbon content can enhance resistance to intergranular corrosion and improve weldability. The addition of Mo helps to better prevent pitting. 304 is a low-carbon stainless steel, whereas 316L is an ultra-low-carbon stainless steel. A lower carbon content reduces the likelihood of intergranular corrosion; however, both 304 and 316L are sensitive to Cl ions. 304 has much weaker resistance to Cl- compared to 316L, and in environments with high Cl- concentrations, 316L is generally used. 2. The difference between 316L and 304 is significant, mainly in terms of intergranular corrosion. 304 belongs to low-carbon stainless steel, while 316L belongs to ultra-low-carbon stainless steel. The higher the carbon content, the weaker the steel’s resistance to intergranular corrosion; therefore, 316L has better intergranular corrosion resistance than 304. 3. The maximum carbon content in 316L stainless steel is 0.03; it can be used in applications where annealing is not possible after welding and where maximum corrosion resistance is required. In general, 316L has better corrosion resistance and intergranular corrosion resistance than 304 ； In terms of welding properties, 316L performs better than 304 due to its lower carbon content and other overall advantages ； In terms of mechanical properties, 304 has higher strength than 316L ； In terms of machinability, 316L has good cutting properties.

1. 304 stainless steel: It possesses good corrosion resistance, heat resistance, strength at low temperatures, and mechanical properties. It is suitable for hot working such as stamping and bending, does not experience hardening due to heat treatment, and is non-magnetic. It is widely used in household items, cabinets, indoor piping, water heaters, boilers, bathtubs, automotive parts, medical devices, building materials, the chemical industry, the food industry, agriculture, and ship components. 2. 316L stainless steel: Mo (2-3%) is added to this steel, which gives it excellent corrosion resistance and high-temperature strength； 316L has a lower carbon content than 316, and it possesses higher high-temperature creep strength. It can be used in harsh conditions, exhibits good work hardening properties, and is non-magnetic. It is suitable for equipment used in seawater environments, as well as in the chemical, dye, papermaking, oxalic acid, and fertilizer production industries, as well as in the photography and food industry and coastal facilities.

1. 304 stainless steel: It possesses good corrosion resistance, heat resistance, strength at low temperatures, and mechanical properties. It is suitable for hot working such as stamping and bending, does not experience hardening due to heat treatment, and is non-magnetic. It is widely used in household items, cabinets, indoor piping, water heaters, boilers, bathtubs, automotive parts, medical devices, building materials, the chemical industry, the food industry, agriculture, and ship components. 2. 316L stainless steel: Mo (2-3%) is added to this steel, which gives it excellent corrosion resistance and high-temperature strength； 316L has a lower carbon content than 316, and it possesses higher high-temperature creep strength. It can be used in harsh conditions, exhibits good work hardening properties, and is non-magnetic. It is suitable for equipment used in seawater environments, as well as in the chemical, dye, papermaking, oxalic acid, and fertilizer production industries, as well as in the photography and food industry and coastal facilities.

1. 304 stainless steel: It possesses good corrosion resistance, heat resistance, strength at low temperatures, and mechanical properties. It is suitable for hot working such as stamping and bending, does not experience hardening due to heat treatment, and is non-magnetic. It is widely used in household items, cabinets, indoor piping, water heaters, boilers, bathtubs, automotive parts, medical devices, building materials, the chemical industry, the food industry, agriculture, and ship components. 2. 316L stainless steel: Mo (2-3%) is added to this steel, which gives it excellent corrosion resistance and high-temperature strength； 316L has a lower carbon content than 316, and it possesses higher high-temperature creep strength. It can be used in harsh conditions, exhibits good work hardening properties, and is non-magnetic. It is suitable for equipment used in seawater environments, as well as in the chemical, dye, papermaking, oxalic acid, and fertilizer production industries, as well as in the photography and food industry and coastal facilities.

1. The main difference in chemical composition between 316L and 304 is that 316L contains Mo. Molybdenum is added to austenitic stainless steels to improve their thermal strength and creep strength, as well as to enhance their resistance to pitting and intergranular corrosion. Mo can passivate the steel surface in both reducing and strongly oxidizing salt solutions, thereby improving the steel’s corrosion resistance and preventing pitting in chloride solutions. Adding Mo can improve resistance to reducing acids and pitting corrosion, while reducing carbon content can enhance resistance to intergranular corrosion and improve weldability. The addition of Mo helps to better prevent pitting. 304 is a low-carbon stainless steel, whereas 316L is an ultra-low-carbon stainless steel. A lower carbon content reduces the likelihood of intergranular corrosion; however, both 304 and 316L are sensitive to Cl ions. 304 has much weaker resistance to Cl- compared to 316L, and in environments with high Cl- concentrations, 316L is generally used. 2. The difference between 316L and 304 is significant, mainly in terms of intergranular corrosion. 304 belongs to low-carbon stainless steel, while 316L belongs to ultra-low-carbon stainless steel. The higher the carbon content, the weaker the steel’s resistance to intergranular corrosion; therefore, 316L has better intergranular corrosion resistance than 304. 3. The maximum carbon content in 316L stainless steel is 0.03; it can be used in applications where annealing is not possible after welding and where maximum corrosion resistance is required. In general, 316L has better corrosion resistance and intergranular corrosion resistance than 304 ； In terms of welding properties, 316L performs better than 304 due to its lower carbon content and other overall advantages ； In terms of mechanical properties, 304 has higher strength than 316L ； In terms of machinability, 316L has good cutting properties.

The different compositions result in different properties. The chemical composition percentage for 316L is: C≤0.03, Si≤1.00, Mn≤2.00, P≤0.035, S≤0.03; Ni: 12.0–15.0, Cr: 16.0–18.0, Mo: 2.0–3.0. The chemical composition percentage for 304 is: carbon ≤0.08, silicon ≤1.00, manganese ≤2.00, phosphorus ≤0.045, sulfur ≤0.03; nickel 8.0–10.5, chromium 18–20. 304 and 316L are different materials: 304 is ordinary stainless steel, while 316L is stainless steel containing molybdenum and having a low carbon content. Their areas of application also differ – 316L is generally used in environments with dilute sulfuric acid. 304 has lower corrosion resistance, and in terms of price, 316L is much more expensive than 304. It’s probably more than twice the price.

The main difference in chemical composition between 316L and 304 is that 316L contains Mo.

The main difference in chemical composition between 316L and 304 is that 316L contains Mo； There is a significant difference between 316L and 304, mainly in terms of intergranular corrosion ；

1. 316L grade: 022Cr17Ni12Mo2; 304 grade: 00Cr19Ni10； 316L contains Mo and has a higher nickel content, making it more corrosion-resistant than 304. 2. 304 is used in environments with moderate corrosion, while 316L is used in conditions with severe corrosion; however, its price is much higher, so this factor should be taken into consideration when making a choice. 3. 316L stainless steel is suitable for equipment used in seawater, as well as for production equipment in the chemical, dye, papermaking, oxalic acid, fertilizer industries, etc ； Photography, food industry, facilities in coastal areas, ropes, CD poles, bolts, nuts. 304 stainless steel is suitable for: household items (tableware of categories 1 and 2, cabinets, indoor piping, water heaters, boilers, bathtubs), auto parts (windshield wipers, mufflers, molded products), medical devices, building materials, the chemical industry, the food industry, agriculture, and ship components.