X20Cr13 | X30Cr13 Stainless Steel

X20Cr13 and X30Cr13 steel both belong to the European standard EN10088. As the representative steels of high chromium stainless steels,they both belong to martensitic stainless steels and have good machining performance.

After heat treatment(quenching and tempering),they all have excellent corrosion resistance,polishing properties,and high strength and wear resistance.However, in comparison, on the basis of the same chromium content, X20Cr13 has a lower content, which means that the corrosion resistance is relatively high and the strength is relatively low.The hardness of X30Cr13 is relatively high, and it is more suitable for the manufacture of plastic molds that are subjected to high load, high wear resistance and corrosive media.

WHAT DOES X20Cr13 | X30Cr13 MEAN?

To solve this problem, we must first understand the naming rules of stainless steel in Germany,and then we will briefly talk about it.

According to the DIN 17006 system steel number representation method, an element in the steel above 5% is called high alloy steel, and the steel number begins with the letter X,followed by a number representing the average carbon content of the steel and the chemical symbols of the alloying elements which are sorted by content.the last is the average percentage value of the content of each main alloying element (rounded to an integer).

For example: X10CrNi18-8 means stainless steel with w(C) of 0.10%, w(Cr) of 18% and w(Ni) of 8%

Here X20Cr13 and X30Cr13,According to the above rules, we know that X20Cr13 and X30Cr13 contain an average carbon content of 0.2% and 0.3% respectively with Cr content of about 13%.

Another representation method is the digital steel number representation method of the DIN17007 system.It is represented by 7 digits, and its general form is shown as follows

X XXXX XX

The first number X indicates the material category, the 2nd-5th XXXX indicates the steel grade group, and the 6th and 7th numbers XX are additional numbers indicating the steel’s manufacturing method and heat treatment state.

Among the numbers indicating the steel grade group, the most important are the second and third digits.The 4th and 5th digits have no certain rules, or are distinguished by carbon content or alloy content.

40 to 45 represent stainless steel groups, and their specific meanings are as follows

40——Ni<2.5%, without Mo, Nb and Ti
41——Ni<2.5%, with Mo, without Nb and Ti
43——Ni≥2.5%, without Mo, Nb and Ti
44——Ni≥2.5%, with Mo, without Nb and Ti
45——contains special added elements

In this article, the digital code for X20Cr13 is 1.4021, while the digital code for X30Cr13 is 1.4028.

X20Cr13 | X30Cr13 STEEL CHEMICAL COMPOSITION

Grade	C	Si	Mn	P	S	Cr
X20Cr13/1.4021	0.16-0.25	≤1.0	≤1.5	≤ 0.04	≤ 0.015	12-14
X30Cr13/1.4028	0.26-0.35	≤1.0	≤1.5	≤ 0.04	≤ 0.015	12-14

X20Cr13 | X30Cr13 STEEL EQUIVALENT GRADE

	X20Cr13	X30Cr13
China	20Cr13/2Cr13	30Cr13/3Cr13
USA	420/S42000	420/S42000
Japan	SUS420J1	SUS420J2

X20Cr13 | X30Cr13 STEEL PHYSICAL PROPERTY

	X20Cr13/1.4021		X30Cr13/1.4028
Density, g/cm3	7.75		7.76
Ac1,℃	820		780
Ar1,℃	820		780
Ms,℃	300-350		240
Melting point,℃	1470-1510		1365
Specific heat capacity，(0~100℃),kj/(kg.k)	0.46		0.47
Thermal conductivity W/(m.K)	100℃	500℃	100℃	500℃
	22.2	26.4	25.1	25.5
Linear expansion coefficient,10^-6/k	0~100℃	0~500℃	0~100℃	0~500℃
	10.3	12.2	10.5	12.0
Resistivity（20℃),Ω.mm2/m	0.55		0.52
Longitudinal modulus of elasticity （20℃)，kN/mm2	200		219
Magnetic	Magnetic		Magnetic

X20Cr13 | X30Cr13 STEEL FORGING

	X20Cr13	X30Cr13
Initial Forging Temperature	1100℃-1150℃	1100℃
Final Forging Temperature	850-900℃	Min 850℃
Forging Ratio	≥4:1	≥4:1
Post-Forging Treatment	Slow cooling	Slow cooling

X20Cr13 | X30Cr13 STEEL HEAT TREATMENT

X20Cr13 | X30Cr13 Annealing

	X20Cr13	X30Cr13
AnnealingTemperature	730-790℃	730-790℃
Cooling Method	Furnance Cooling	Furnance Cooling
Hardness	160-187HB	<207HB

X20Cr13 | X30Cr13 Steel Mechanical Properties in Annealed condition

Grade	Tensile Strength	Elongation	Hardness
X20Cr13	Max 700Mpa	Min 15%	≤225HBW
X30Cr13	Max 740Mpa	Min 15%	≤235HBW

X20Cr13 | X30Cr13 Quenching & Tempering(QT)

	X20Cr13+QT	X30Cr13+QT
Quenching temperature	950-1050℃	950-1050℃
Cooling Type	oil,air	oil,air
Tempering temperature	200-350℃	200-350℃

What is X20Cr13+QT650 and X20Cr13+QT750?

In fact, QT650 indicates the state of heat treatment, QT is quenching and tempering heat treatment, and 650 indicates that the tensile strength after quenching and tempering reaches more than 650Mpa.
In the same way, QT750 means that the tensile strength after quenching and tempering heat treatment reaches more than 750Mpa.