Stainless Steel Grade AISI 309 | EN 1.4828 | DIN X15CrNiSi20-12

AISI 309 | EN 1.4828 | DIN X15CrNiSi20-12 - is an austenitic high-alloy stainless steel with a large amount of chromium. It has very high corrosion resistance and strength than other similar steels. In fact, it is a standard stainless steel that is used to make furnace parts and other high-temperature parts and components.

Physical properties

Table No. 1: physical properties of stainless steel grade AISI 309 | EN 1.4828 | DIN X15CrNiSi20-12
Density g/cm³	7,9
Specific heat capacity J/kg K	500
Thermal conductivity W/m K	15
Specific electrical resistance Ω mm² / m	0,85
Magnetic properties	non-magnetic

Table No. 2: physical properties of stainless steel grade AISI 309 | EN 1.4828 | DIN X15CrNiSi20-12
Temperature	+20°С	+200°С	+400°C	+600°С	+800°С	+1000°С
Coefficient of linear expansion, 10^-6/°C	16,5	16,5	17,5	18,0	18,5	19,5

Technological properties

⓵ Welding

Weldable using all normal welding processes without preheating. Small heat inputs should be used during welding and no post weld heat treatment is required. Fillers may be used during welding.

⓶ Forging

Forging is usually done at 1150 °C - 800 °C. Then rapid cooling in air or water is necessary. As a rule, heat treatment follows forging.

⓷ Mechanical processing

The formation of carbides in AISI 309 | EN 1.4828 leads to increased wear of cutting tools. In addition, rapid hardening and low thermal conductivity require the use of suitable cutting and machining equipment of good quality. It is recommended to carry out machining under annealing conditions using cutting tools, machining with hard metal coating and special machining parameters.

⓸ Cold processing

AISI 309 can be drawn, stamped, etc., even if it has a high degree of strain hardening. After cold working, annealing should be performed to reduce internal stress.

⓹ Annealing

This stainless steel is annealed at 1038 - 1121 °C and then quenched in water.

⓺ Hardening

EN 1.4828 does not react to heat treatment. The strength and hardness of this alloy can be increased by cold working.

Mechanical properties

Table: mechanical properties of stainless steel grade AISI 309 | EN 1.4828 | DIN X15CrNiSi20-12
Tensile strength, min., MPa	500 - 750
Yield strength, 0.2%, MPa	230
Relative elongation, min., %	30
Hardness, HB type	223
Resistance to air up to ℃	1000
Modulus of elasticity kN/mm²	196

Table: chemical composition of steel grade AISI 309 | EN 1.4828 | DIN X15CrNiSi20-12
Chemical composition of steel grade AISI 309 \| EN 1.4828 \| DIN X15CrNiSi20-12
С	Si	Mn	P	S	Cr	Ni	N	Fe
<0,20	1,50-2,50	<2,00	<0,045	<0,015	19,0-21,0	11,0-13,0	<0,10	Other

The long service life and excellent performance properties of stainless steel AISI 309 | EN 1.4828 | DIN X15CrNiSi20-12 allow it to be widely used in the industrial sector: from mechanical engineering to oil refining.

Products made of AISI 309 steel grade are used in mechanical engineering, oil refining, metallurgy, chemical and mining industries. Various structural elements that will be used in a high-temperature environment (up to 1000 ℃) without load or in a lightly loaded state are made of this metal grade. Typical examples of practical application of the alloy are furnace fittings, conveyor elements, cementation molds, as well as various containers and vessels operating under pressure at high temperatures in an aggressive environment.