• Material

1.4112 (S46990, S44003, sus440b, X90CrMoV18)

• Chemical composition

C: 0.85～0.95%; Si: ≤1.0%; Mn: ≤1.0%; P: ≤0.04%; S: ≤0.015%; Cr: 17～19%; Mo: 0.9～1.3%; V: 0.07～0.12 %; Fe: balance

• Material properties

Density: 7.7g/cm³; tensile strength: 590MPa; yield strength: 245MPa; elongation: 15%; hardness HBW: 269; quenching and tempering hardness: 55HRC.

• Mechanical behavior

1.4112 is a high carbon martensitic stainless steel. Its mechanical properties mainly include strength, hardness, toughness, etc. Due to its high carbon and chromium content, this steel type has high strength and hardness and can withstand greater pressure and wear. At the same time, due to its good toughness, this steel type is not easy to embrittle and can be used in more complex environments. Resistant to corrosion from mild atmosphere, fresh water vapor, ammonia, many petroleum products and organic materials, and a variety of weakly acidic environments. The annealing temperature is very low, and the hardness after quenching is high. The hardness usually reaches HRC56-58. It has good corrosion resistance (magnetic) and strong toughness.

• Application areas

Because 1.4112 stainless steel has excellent corrosion resistance and mechanical properties, it is widely used in petroleum, chemical industry, marine engineering, automobiles, food and other fields. In the petroleum and chemical industries, due to its excellent corrosion resistance, it is used to manufacture reactors, pipelines and other equipment. In the field of marine engineering, it is used to manufacture key parts of ships and offshore platforms. In the automotive field, it is used to manufacture components such as exhaust systems and fasteners. In the food field, it is used to manufacture kitchen equipment and food processing equipment due to its good hygienic properties.

• Process performance

The process properties of 1.4112 stainless steel mainly include welding, heat treatment and processing properties. This steel type has good welding performance and can be welded using various welding methods. Heat treatment can improve its mechanical properties and corrosion resistance, but care needs to be taken to prevent cracking or deformation caused by overheating or overcooling. It has good processing performance and can be used for turning, milling, drilling, tapping and other processing operations. Its disadvantages are that it is sticky and heats up quickly, but it is easier to sand than any carbon steel and is much easier to cut with a hand saw.

• Parts processing requirements

The highest processing accuracy is 0.03mm, the highest smoothness is Rz1um, and the concentricity of all outer circular surfaces is within 0.03mm.

• Processing

Casting: using medium temperature wax lost wax precision casting.

Machining: The lathe holds one end of the claw clamp, cooperates with the center frame, processes the outer circle as a precision reference, then processes the inner hole, performs rough turning and fine turning to process the inner and outer surfaces, and finish turning the outer circles and end faces of both ends.

• Detailed machining process

1.Hold the inside hole on two side. Rough Machining two side (Size10,15,16,20,27,28,30,35,36,37,38)and the whole out surface;

2.Clamp left side, and hold OD surface. Machining the right side and inside holes.  Rough machining size NO.27---45. Finish machining size NO.72;

3.Clamp right side, and hold OD surface, Rough machining the left side, Rough machining size NO.9,10,11,12,13,14,15,16,20,21and 57—64;

4.Hold inside hole from right side,It is the base A. Hold the part from left side hole. Do the final machining on both side. Machining size NO.9, 10-16,20,21. And 23-45;

5.CNC machining the holes,thread on both side;

6.Machining Size NO. 2,4,6,8. 46—56.

Grinding and polishing: reserve 0.05mm for grinder processing allowance, internal grinding + honing.

Heat treatment: Annealing, slow cooling at 800~920℃; quenching, oil cooling at 1000~1050℃; tempering, 200~300℃; 96h quenching and tempering heat treatment.

• Material report

• CMM testing  

• Pressure test