What is 1.4006 Stainless Steel?

What Is 1.4006 Stainless Steel?

1.4006, designated X12Cr13 in EN 10088-1, is a martensitic stainless steel with approximately 12% chromium and 0.10% carbon. It is the European standard equivalent of AISI 410, UNS S41000, JIS SUS410 and Chinese GB 12Cr13. The martensitic structure formed by quenching gives the steel high hardness and wear resistance, while the chromium content provides moderate corrosion resistance in mild environments.

Designation system	Grade
EN	1.4006, X12Cr13
AISI	410
UNS	S41000
JIS	SUS410
GB	12Cr13

Chemical Composition

Element	EN 10088-1	ASTM A240
C	0.08-0.15%	≤0.15%
Si	≤1.00%	≤1.00%
Mn	≤1.50%	≤1.00%
P	≤0.040%	≤0.040%
S	≤0.015%	≤0.030%
Cr	11.50-13.50%	11.50-13.50%

Mechanical Properties

The values below are typical for the annealed and for the quenched-and-tempered condition.

Condition	Rp0.2	Rm	Elongation	Hardness
Annealed	≈275 MPa	≈500 MPa	≈20%	≤217 HBW
Quenched and tempered	≥345 MPa	≥655 MPa	≥15%	up to ≈45 HRC

Hardness after tempering depends on the tempering temperature selected by the user; lower tempering temperatures give higher hardness and lower ductility.

Heat Treatment

Soft annealing for machinability: heat to 800-900°C and cool slowly in the furnace. Hardening: austenitize at 980-1010°C and quench in oil or air to form martensite. Tempering: select 150-200°C for maximum hardness with limited ductility, 250-400°C for a balance of hardness and toughness, or 600-700°C for maximum toughness at reduced strength. Avoid tempering in the 400-600°C range, where impact toughness drops due to tempered martensite embrittlement.

Corrosion Resistance and Applications

1.4006 resists atmospheric corrosion, fresh water, steam and mild organic media. It is not recommended for chloride-rich, acidic or marine environments. Typical applications: valve bodies and stems, pump shafts, impellers, fasteners, steam turbine blades, kitchen knives and cutlery, springs for moderate duty, surgical instruments and machine parts requiring wear resistance with moderate corrosion performance.

Frequently Asked Questions

What is 1.4006 equivalent to?

1.4006 (X12Cr13) is equivalent to AISI 410, UNS S41000, JIS SUS410 and Chinese GB 12Cr13.

Can 1.4006 be hardened?

Yes. After austenitizing at 980-1010°C, oil quenching and tempering, hardness of about 40-45 HRC is achievable, with tensile strength above 650 MPa.

Is 1.4006 weldable?

Welding is possible with preheating at 200-300°C, austenitic filler such as ER309L for most joints, and a post-weld tempering treatment, because the weld zone forms hard untempered martensite on cooling.

Is 1.4006 corrosion resistant?

Moderately. It is suitable for atmospheric, fresh-water and steam service, but not for chlorides, strong acids or marine atmospheres.

What is the difference between 1.4006 and 1.4021?

1.4021 (X20Cr13) has a higher carbon range of 0.16-0.25%, giving higher hardness and wear resistance at the cost of lower toughness and weldability; 1.4006 is the more ductile member of the pair.

Is 1.4006 magnetic?

Yes. As a martensitic grade it is magnetic in all conditions.