Steel 20x13: characteristics, application, analogues, composition

General characteristics of the alloy

The main alloying element in the production of grade 20x13 (the characteristics of steel largely depend on the concentration of chemicals in the composition) was chromium. Its addition to the metal composition is carried out over a long period. The main characteristics of plastic are as follows:

Limited degree of weldability. The metal in question is characterized by a low degree of machinability. In most cases, the material is heated to increase the degree of weldability.
Heat resistance and low thermal conductivity are properties that significantly expand the range of the material under consideration. Corrosion-resistant, heat-resistant steel 20X13 can be operated at temperatures up to 700 degrees Celsius. Increasing the temperature to higher levels leads to a significant decrease in the properties of the material: hardness, resistance to deformation, and others.
Hardness is maintained at a level of 126-197 MPa, depending on whether heat treatment was carried out.
The structure is prone to temper brittleness; it is possible to carry out cutting processing.

Mechanical properties of steel 20Х13 at different temperatures

The main characteristics of the alloy determine the possibility of its use in the manufacture of a wide variety of products. If necessary, they can be improved by heat treatment, for example, hardening or annealing.

Steel 20Х13 corrosion-resistant, heat-resistant, martensitic

Substitutes for steel 20Х13

Steel 12Х13, 14Х17Н2

Foreign analogues

Germany DIN	Brand	Х20Cr13
	Number	1.4021
USA (AISI, SAE, ASTM)		420
France (AFNOR)		Z20С13
UK (BS)		420S37
Sweden (SS)		2303
Italy UNI		X20Cr13

IMPORTANT!!! The possibility of replacement is determined in each specific case after assessing and comparing the properties of steels

Decoding steel 20Х13

The number 20 indicates the average carbon content in hundredths of a percent, i.e. for steel 20Х13 this value is 0.20%.

The letter “X” indicates the chromium content of the steel. The number 13 after the letter “X” indicates the approximate amount of chromium in steel as a percentage, rounded to the nearest whole number, i.e. chromium content about 13%.

Type of delivery

Long products, including shaped steel: GOST 5949-75, GOST 2590-88, GOST 2591-88, GOST 2879-88, GOST 18968-73, GOST 19442-74.
Calibrated rod GOST 8559-75, GOST 8560-78, GOST 7417-78.
Polished rod and silver steel GOST 14955-77, GOST 18907-73.
Thick sheet GOST 7350-77. Thin sheet GOST 5582-75.
Tape GOST 4986-79.
Strip GOST 4405-75, GOST 103-76, GOST 18968-73.
Wire GOST 18143-72.
Forgings and forged blanks GOST 1133-71, GOST 18968-73, GOST 25054-81.
Pipes GOST 14162-79.

Characteristics and purpose

Steel 20Х13 belongs to corrosion-resistant, heat-resistant martensitic steels (main structure is martensite). Steel 20X13 is used for the manufacture of parts with increased ductility, subjected to shock loads and operating at temperatures up to 450-500 ° C, as well as products exposed to mildly aggressive environments at room temperature.

Weldability

Steel 20X13 has limited weldability. Welding methods RDS, ArDS and KTS. Heating and subsequent heat treatment are used depending on the welding method, type and purpose of the structure.

Maximum permissible temperature for using steel 20Х13 in environments containing ammonia

steel grade	Temperature of application of steels, °C at partial pressure of ammonia, MPa (kgf/cm)
steel grade	St. 1(10) to 2(20)	St. 2(20) to 5(50)	St. 5(50) to 8(80)
20Х13	540	540	540

Maximum permissible temperature for using steel 20Х13 in hydrogen-containing environments

steel grade	Temperature, °C, at partial pressure of hydrogen, PH2, MPa (kgf/cm2)
steel grade	1,5(15)	2,5(25)	5(50)	10(100)	20(200)	30(300)	40(400)
20Х13	510	510	510	510	510	510	510

NOTE

The parameters for using steels indicated in the table also apply to welded joints.
The partial pressure of hydrogen is calculated by the formula: PH2 = (C*Pp)/100, where C is the percentage in the system; PH2—hydrogen partial pressure; Pp is the operating pressure in the system.

Resistance of steel 20Х13 against crevice erosion

Durability group	Point	Erosion resistance against steel 12X18H10T
Persistent	2	0,75-1,5

Application of steel 20Х13 for the manufacture of main parts of nuclear power plant fittings

steel grade	Type of semi-finished product or product	Maximum permissible temperature of use, °C
20Х13 GOST 5632, GOST 24030	Sheets, pipes, forgings, long products. Fasteners	600

Chemical composition, % (GOST 5632-2014)

WITH	Si	Mn	Cr	Ni	Ti	S	R
no more	Si	Mn	no more			S	R
0,16-0,25	0,8	0,8	12,0-14,0	—	—	0,025	0,030

Chemical composition, % (GOST 5632-81)

WITH	Si	Mn	Cr	S	R	Ti	Cu	Ni
WITH	no more		Cr	no more
0,16-0,25	0,8	0,8	12,0-14,0	0,025	0,030	0,2	0,30	0,6

Physical properties

Modulus of normal elasticity E, GPa

steel grade	At test temperature, °C
steel grade	20	100	200	300	400	500	600	700	800	900
20X13	218	214	208	200	189	181	169	—	—	—

Modulus of elasticity in torsional shear G, GPa

steel grade	At test temperature, °C
steel grade	20	100	200	300	400	500	600	700	800	900
20X13	86	84	80	78	73	69	63	—	—	—

Density ρ kg/cm3 at test temperature, °C

Steel	20	100	200	300	400	500	600	700	800	900
20X13	7670	7660	7630	7600	7570	7540	7510	7480	7450	—

Thermal conductivity coefficient λ W/(m*K) at test temperature, °C

Steel	20	100	200	300	400	500	600	700	800	900
20X13	—	26	26	26	26	27	26	26	27	28

Electrical resistivity ρ nom*m

steel grade	At test temperature, °C
steel grade	20	100	200	300	400	500	600	700	800	900
20X13	588	653	730	800	884	952	1022	1102	—	—

Linear expansion coefficient α*106, K-1, at test temperature, °C

Steel	20-100	20-200	20-300	20-400	20-500	20-600	20-700	20-800	20-900	20-1000
20X13	10,2	11,2	11,5	11,9	12,2	12,8	12,8	13,0	—	—

Specific heat capacity c, J/(kg*K), at test temperature, °C

Steel	20-100	20-200	20-300	20-400	20-500	20-600	20-700	20-800	20-900	20-1000
20X13	112	117	123	127	132	137	147	155	159	—

Temperature of critical points, °C

Ac1	Ac3	Ar3	Ar1	Mn
810	900	660	710	320

Mechanical properties

GOST	Delivery status	Széchenyi	σ0.2, MPa	σв, MPa	δ5, %	ψ%	KCU, J/cm2
GOST	Delivery status	Széchenyi	no less
GOST 5949-75	Bar. Hardening from 1000-1050 °C in air or oil; holiday at 600-700 °C, cool. in air or oil	60	635	830	10	50	59
GOST 5949-75	Bar. Hardening from 1000-1050 °C in air or oil; holiday at 660-770 °C, cool. in air, oil or water	60	440	650	16	55	78
GOST 18907-73	Ground rod, processed to a specified strength	1-30	—	510-780	14	—	—
GOST 7350-77	The sheet is hot-rolled or cold-rolled. Hardening from 1000-1050 °C in air; holiday at 680-780 °C, cool. in air or with an oven (transverse samples)	St. 4	372	509	20	—	—
GOST 25054-81	Forging. Hardening from 1000-1050 °C in air or oil	1000	441	588	14	40	39
GOST 4986-79	Cold rolled strip.	Up to 0.2	—	500	8	—	—
GOST 4986-79	Annealing or tempering at 740-800 °C	0,2-2,0	—	500	16	—	—
GOST 18143-72	Heat treated wire	1,0-6,0	—	490-780	14	—	—

Mechanical properties of workpieces with a cross-section of 14 mm depending on the tempering temperature

tref.°С	σ0.2, MPa	σв, MPa	δ5, %	ψ%	KCU, J/cm2	Hardness HRCе
200	1300	1600	13	50	81	46
300	1270	1460	14	57	98	42
450	1330	1510	15	57	71	45
500	1300	1510	19	54	75	46
600	920	1020	14	60	71	29
700	650	78	18	64	102	20
700	650	78	18	64	102	20

NOTE. Hardening at 1050 °C in air.

Mechanical properties at elevated temperatures

tsp.°C	σ0.2, MPa	σв, MPa	δ5, %	ψ%	KCU, J/cm2
Normalization at 1000-1020 °C; holiday at 730-750 °C. At 20 °СНВ 187-217
	20	510	710	21	66	64-171
	300	390	540	18	66	196
	400	390	520	17	59	196
	450	370	480	18	57	235
	500	350	430	33	75	245
550	275	340	37	83	216
Sample with a diameter of 6 mm and a length of 30 mm, rolled. Deformation speed 16 mm/min; strain rate 0.009 1/s
	800	59	70	51	98	—
	850	—	—	43	—	—
	900	—	—	66	—	—
	1000	39	61	59	—	—
	1150	21	31	84	100	—

Mechanical properties of rods at negative temperatures

tsp.°C	σ0.2, MPa	σв, MPa	δ5, %	ψ%	KCU, J/cm2
Section 25 mm. Normalization at 1000 “C, cool. on air; holiday at 680-750 °C
	+20	540	700	21	62	76
	-20	560	730	22	59	54
	-40	580	770	23	57	49
	-60	570	810	24	57	41
	Section 14 mm. Hardening at 1050 °C in air; tempering at 600 °C
+20		—	—	—	—	71
-20		—	—	—	—	81
-60		—	—	—	—	64

Mechanical properties during long-term strength testing

tsp.°C	Creep limit, MPa	Creep rate, %/h	tsp.°C	Long-term strength limit, MPa	τ, h
450	125	1/100000	450	289	10000
470	75	1/100000	470	191	10000
500	47	1/100000	500	255	100000
550	29	1/100000	550	157	100000

NOTE. Fatigue limit σ-1 = 367 MPa at n = 107 (smooth samples).

Mechanical properties depending on thermal exposure

Heat treatment	Heat exposure		σ0.2, MPa	σв, MPa	δ5, %	ψ%	KCU, J/cm2
tsp.°C	τ, h
Normalization at 1000-1020 °C, cool. on air; holiday at 730-750 °C, cool. on air						500		5000	500	690	20	62	108
10000	420	670	23	65	118
550		1000	450	690	26	65	—
10000	440	660	24	63	108
600		3000	450	660	21	60	78
10000	380	630	23	63	147

Technological properties

Forging temperature, °C: beginning 1250, end 850. Sections up to 150 mm are cooled in air, sections 150-400 mm require low-temperature annealing with one supercooling.

Cutting machinability - Kv tv.spl = 0.7 and Kv b.st = 0.45 in the quenched and tempered state at HB 241 and σw = 730 MPa.

Flock sensitivity - not sensitive.

Tendency to temper brittleness - prone.

Corrosion resistance

Wednesday	Temperature, °C	Test duration, h	Corrosion depth, mm/year
Distilled water or steam	100	—	0,1
Soil water 20	—	1,0
Sea water	20	720	0

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Chemical composition

In many ways, 20x13 steel resembles its analogues, which also contain a large amount of chromium. The chemical composition is represented by a combination of the following substances:

Carbon largely determines the hardness and strength of the material, as well as the degree of weldability. In the case under consideration, the carbon concentration can vary from 0.16 to 0.25%.
Chromium is considered the main alloying element. About 12-14% of this chemical is added to the alloy composition. It is chromium that determines heat resistance and corrosion resistance.
Manganese and nickel are not the main elements of the alloy in question; their concentration is no more than 0.6%.

Almost all metals contain phosphorus and sulfur. These chemical elements are present in the composition at a concentration of no more than 0.03%.

Stainless steel sheet 20X13

Foreign manufacturers also produce alloys with similar chemical compositions. For example, the Japanese analogue of steel 20x13 was called SUS420J1, the French alloys z20c13 and X20Cr13.

Steel composition

Now let's look at the most important component of any metal-containing alloy - its composition.

Thanks to official technical documents, anyone can determine with a high degree of accuracy exactly what elements are included in 20X13 steel. Their list is as follows:

Carbon - 0.2% - an element without which steel cannot exist. It is this that gives soft iron strength and hardness. However, at this content the alloy still remains relatively ductile and can be machined, in some cases even without preheating.
Silicon - 0.6% - an alloying additive that improves the structure of steel and allows it to better withstand overheating.
Manganese - 0.6% - an additive in many ways similar to the previous one, however, manganese not only increases the hardenability of steel, but also increases its viscosity.
Nickel - 0.6% - again an alloying element that increases the thermal stability of steel, its overall ductility and strength.
Chromium - 13% - is no less important than carbon, because chromium is responsible for the strength of steel, its corrosion resistance, hardenability and conductivity.

At this stage, we can add that 20X13 is a heat-resistant steel that has exceptional resistance to elevated temperatures, if, of course, we compare it with other technical steels. In addition, the alloy is extremely insensitive to corrosion and oxidation due to the high chromium content in the composition.

If you know the characteristics of steel 20X13, the use of this alloy ceases to be a secret. With a high degree of probability these may be parts operating at high temperatures.

Application of steel 20x13

Steel 20x13 has a large number of features that determine its wide distribution. Heat resistance and corrosion resistance are valued in the following cases:

Mechanical engineering industry.
In the production of turbine blades, which are exposed to high temperatures and pressures.
When creating fasteners with high strength and corrosion resistance.
Production of parts that are exposed to atmospheric precipitation and organic sludge.
In the manufacture of rings for various purposes.
Aviation industry.
Production of products operating at low temperatures and in aggressive chemical environments.
When creating parts for compressor machines that work with non-toxic gases.

Tube boards 20x13

Heat treatment can significantly improve the performance characteristics of the alloy. This is due to the fact that with strong heating, the crystal lattice is rearranged to strengthen the structure and increase the hardness of the surface layer. The use of 20x13 steel made it possible to significantly extend the service life of products that serve in difficult operating conditions.

GOSTs and other standards for steel 20Х13

In order for the produced metals to be used in certain conditions, Gosstandart is used during their production. Steel 20×13 (GOST determines the release form and basic qualities) is manufactured taking into account the following standards:

Forgings are supplied in square and round shapes.
When using an alloy, wires with high performance characteristics can be produced.
Rolled products with different sheet thicknesses, which are characterized by heat resistance and corrosion resistance, are supplied to production lines.
Forged and hot-rolled strips are supplied to industry.
Shaped profiles.

The classification of steel 20x13 determines a high concentration of chromium, which leads to a decrease in some performance qualities. An example is the inability to use sheet metal to make a body when using a welding machine. The established standard 20x13 GOST also determines the possibility of additional processing, which makes the structure more dense and durable, resistant to various types of influence.

Download GOST 5632-72

welding steel 20Х13 semi-automatically

and I accidentally acquired a ton of this steel, 5 mm thick.
The question is, it is impossible to anneal large-sized products, in my conditions of course. What are the properties of unannealed seams of this steel? especially at operating temperatures of -30-40? the seams are mechanically loaded only by their own stresses and a little more... what kind of trouble can be expected from an unannealed seam in the long term?

Dont be upset. Please note Nightfeather's :

- welding method (apparently more suitable for you): mechanized in an environment of inert gases (argon), or better in a mixture of 43% Ar + 55% He + 2% CO2 (this is too cool, only the Germans can anneal such 98% Ar +2%CO2 is quite satisfactory) on a direct current of reverse polarity.

— welding materials: austenitic solid wire with low carbon content, high nickel content in the deposited metal, high elongation type 309L, 309L Si (domestic type Sv.-08Х25Н13БТУ). Diameter 1.2 (I hesitate, I would put 1 for your case for the root, in no case in one pass) mm.

— preparation of edges: all butt edges must be grooved, all corner edges must have a guaranteed gap of at least a millimeter. I think this will allow the crystals to grow in the desired direction, which will to some extent reduce the risk of cracks. After all, we are surfacing metal with an austenitic structure.

— assembly of joints: using assembly devices. NO POCKETS. This will allow free shrinkage of the metal of the first welds in the structure and reduce overall welding stresses.

— welding modes:

shielding gas consumption - 12-15 l/min with a burner nozzle diameter of 16-18 mm (+ lens).

wire feed speed - 4-5 m/min for root, 6-7 m/min for base

arc voltage - 17-19V root, 20-22V base (I would experimentally select the minimum possible arc length)

welding current - 100-120A root 160-180A (also not a clear-cut question). Indeed, it is not good to force the currents and welding speed (you can read it here)

wire stick out - as expected 10 F of the electrode (if the machine is USSR without synergetics and everything else)

-welding technique: without “stirring” the electrode in the weld pool to reduce the proportion of base metal in the weld metal. The welding order must be followed as prescribed in the ABC books.

If the seam is double-sided, I think the last one should be the roller facing the aggressive environment.

Add to this heating before and after welding in order to get into QUIET and not shock the metal.

The modes can be simulated using the Weldability program from Bauman University, if necessary I can send it...

And then all the same night-time KSS for mechanical and chemical testing. analysis... Nickel in steel should not have enough blue brittleness if the technology is followed, maybe a wire is found with molybdenum and finally everything will be in chocolate...

I apologize to the authors of the quotes for copyright infringement. If something is not true, brand it with shame... criticism is useful to me...