Chemical composition of nitrogen-controlled 00Cr17Ni12Mo2 (316NG) steel

Introduction:

00Cr17Ni12Mo2 (316NG) steel is a kind of austenitic steel with high oxidation resistance and moisture resistance. Generally, 00Cr17Ni12Mo2 (316NG) steel is widely used in producing components used in environments related to sea water, acid, alkali and other corrosive media. The research on the chemical composition of 00Cr17Ni12Mo2 (316NG) steel plays an important role in enhancing its corrosion resistance and mechanical properties. This paper aims to investigate the chemical composition of 00Cr17Ni12Mo2 (316NG) steel and its influence on the corrosion resistance.

Chemical Composition of 00Cr17Ni12Mo2 (316NG) Steel

The chemical composition of 00Cr17Ni12Mo2 (316NG) steel is composed of C, Si, Mn, P, S, Ni, Cr, Mo, N and other chemical elements. The most important elements are C, Si, Mn, P, S, Ni, Cr, Mo, which have direct effect on the corrosion resistance, mechanical properties, hardness and other mechanical characteristics of the product. According to the relevant national standard of 00Cr17Ni12Mo2 (316NG) steel, the chemical composition of the steel is as shown in table 1.

Table 1 The chemical composition of 00Cr17Ni12Mo2 (316NG) steel

Steel Element Chemical Composition (%)

C ≤ 0.080

Si ≤ 1.00

Mn ≤ 2.00

P ≤ 0.035

S ≤ 0.030

Ni 10.00～14.00

Cr 16.00～18.00

Mo 2.00～3.00

N ≤ 0.10

Effects of Chemical Composition on Corrosion Resistance of 00Cr17Ni12mo2 (316NG) Steel

C: Carbon is an important element on steel, mainly affecting the mechanical properties, hardness and electrical properties of steel. Carbon helps to improve the strength of steel and reduce the plasticity and toughness of steel. The content of carbon in 00Cr17Ni12Mo2 (316NG) steel is controlled between 0.080% and 0.20%. If the value of C is too high, it will make the steel too hard and brittle, and reduce the toughness of the steel. Generally, the lower the carbon content, the better the corrosion resistance of the steel.

Si: Silicon is an important alloy element in steel, which can improve the hardness, strength and solid solution strengthening effect of steel. The content of silicon in steel is controlled below 1.00%. Si can improve the corrosion resistance of steel and reduce the cutting time and increase the fatigue strength of steel.

Mn：Manganese content is also one of the elements affecting the hardenability of steel. Generally, the higher the Mn content of steel is, the better the hardenability, the better the corrosion resistance and the strong cutting performance is. The maximum manganese content of 00Cr17Ni12Mo2 (316NG) steel is controlled at 2.00%.

P, S：The content of phosphorus and sulfur elements are limited in steel. Too much phosphorus and sulfur will generally produce a lot of eutectic cells in steel, reduce the machinability of the workpiece, and increase the oxidation resistance under high temperature. The content of phosphorus and sulfur elements in 00Cr17Ni12Mo2 (316NG) steel is controlled in the range of 0.035%~0.030%.

Ni and Cr：Nickel and chromium Elements are the main alloying element in austenitic stainless steels. Ni content is an important indicator to measure the performance of steel. Chromium has a strong role in improving the corrosion resistance and preventing oxidation of stainless steel. In 00Cr17Ni12Mo2 (316NG) steel, the minimum Ni content is controlled at 10.00%, and the maximum Cr content is controlled at 18.00%, which can greatly improve the corrosion resistance and obtain better mechanical properties of steel.

Mo：Molybdenum is an important alloying element in austenitic stainless steels, which can greatly improve the corrosion resistance and high temperature strength of the steel. In 00Cr17Ni12Mo2 (316NG) steel, the minimum Mo content is 2.00%. With the increase of molybdenum content, the corrosion resistance of steel increases, but too much molybdenum will reduce the corrosion resistance of steel and reduce the ductility, toughness and plasticity of steel.

Conclusion

In summary, the chemical composition of 00Cr17Ni12Mo2 (316NG) steel is C, Si, Mn, P, S, Ni, Cr, Mo and other chemical elements, which have direct influence on the corrosion resistance, mechanical properties and hardness of the steel. The content of carbon and molybdenum should be controlled between 0.080% and 0.20%, 1.00%, and 2.00% and 3.00%, respectively. Properly increasing the content of nickel and chromium can improve the corrosion resistance of the steel. The appropriate chemical composition is beneficial to the manufacture of components which are used in corrosive environment.

The chemical composition of 00Cr17Ni12Mo2 (316NG) steel is as follows:

Carbon (C): up to 0.02%,

Manganese (Mn): up to 2.00%,

Silicon (Si): up to 0.75%,

Phosphorus (P): up to 0.035%,

Sulphur (S): up to 0.03%,

Chromium (Cr): 16% to 18%,

Nickel (Ni): 10% to 14%,

Molybdenum (Mo): 2.00% to 2.50%,

Carbon plus nitrogen (C+N): up to 0.25%.

00Cr17Ni12Mo2 (316NG) steel is one of the high-temperature austenitic stainless steels. It is of stainless steel austenitic with increased chromium, nickel and molybdenum content. Additionally, the steel has nitrogen added to its composition to further improve its mechanical properties. It has good formability, strength, and resistance to atmospheric corrosion, and intergranular corrosion. It also has resistance to pitting and crevice corrosion in the presence of halide solutions, such as chlorides and bromides, as well as good weldability. 00Cr17Ni12Mo2 (316NG) steel is used in several industries, such as chemical and petrochemical, oil and gas, agricultural, food and beverage, and is also used in the production of power generation equipment and pharmaceutical machinery.