1RK91 is a super high strength and toughness super martensitic stainless steel developed by Sandvik in Sweden in the early 1990s.The UNS number of 1RK91 is S46910, according to the Chinese naming method, it is [TJC STEEL]02Cr12Ni9Mo4Cu2TiAl.

 

Component Specification

STANDARD	Sandvik	ASTM A959-2009
GRADE	1RK91	S46910
C	≤0.02	≤0.03
Si	≤0.50	≤0.70
Mn	≤0.50	≤1.00
P	≤0.020	≤0.030
S[TJC STEEL]	≤0.005	≤0.015
Cr	12	11.0~13.0
Ni	9	8.0~10.0
Mo	4	3.5~5.0
Cu	2	1.5~3.5
Ti	0.9	0.50~1.20
Al	0.4	0.15~0.50

 

Alloy Principle

Different from the traditional idea that alloy carbide or nitrite is the main strengthening phase to make steel reach high strength, 1RK91 steel takes Fe-Cr-Ni as matrix, Cu, Mo, Ti and Al as strengthening elements, [TJC STEEL]and controls C to less than 0.02%.Firstly, the alloying elements are fully dissolved into the matrix through solid solution treatment, and then rapidly cooled to obtain supersaturated lamellar martensite structure of alloying elements.After aging treatment, precipitation hardening phase mainly composed of intermetallic compounds precipitates from martensite matrix, and at the same time, part of martensite is reversed to form reversed austenite.

In 1RK91 steel, intermetallic compound is used as strengthening phase and reversed austenite is used as toughening phase, so that the steel can obtain the best combination of strength and toughness. As an element that has harmful effect on strength and toughness, C is included in the list of controlled existence. [TJC STEEL]The development of this steel is regarded as a breakthrough of ultra-high strength steel in both theory and practice.

 

The Performance Characteristics:

(1)Excellent mechanical properties, can achieve very high tensile strength and hardness level.

(2) Corrosion resistance equivalent to 304L or 316L under corresponding conditions.

(3)Maintains mechanical [TJC STEEL]properties at temperatures up to at least 400°C.

(4) very good relaxation performance.

(5)Good weldability.

 

Applications：

After solid solution at about 1000℃, 1RK91 steel can be cold-processed into metallurgical products such as bars, plates, steel wires and steel strips. After aging treatment at 450 ~ 475℃, 1RK91 steel still has good plasticity and excellent fracture toughness under high strength condition of 3000MPa.At the same time also has excellent cold processing performance and welding performance, good corrosion resistance and anti aging performance.

Sandvik also conducted a Vitro (cytotoxicity) test to verify that 1RK91 steel does not have any potential cytotoxicity and is [TJC STEEL]therefore safe to come into contact with human tissue, body fluids or blood, meeting all relevant allergy and skin irritation testing standards.

1RK91 is used to manufacture parts and instruments used in a variety of complex conditions, such as electric razor mesh blades, medical suture needles, surgical blades, drillers, scissors, files, clamps, punches, guides and other surgical and medical instruments.