Stainless Steel Of MIM 420
Introduction to MIM 420
High strength, hardness, and resistance to corrosion characterize stainless steel 420, a martensitic heat-treatable stainless steel. It is a common steel used in many different applications, including high-end consumer flatware, gauges, pump and valve components, ball bearings, gear shafts, medical surgical and dental equipment, and fasteners.
Additionally, stainless steel 420 is widely used in additive manufacturing (AM) and metal injection molding (MIM) technologies. Successful mass production deployment is accelerated by the qualification of high-strength alloys such as SS 420. The Metal Powder Industries Federation’s (MPIF) MIPIF 35 requirements can be met by our highly quality MIM 420 feedstock.
Stainless Steel with Martensitic Properties
A grade of stainless steel, martensitic steel can be strengthened and toughened by heating and aging.
Due to its strength, resistance to corrosion, and longevity, martensitic stainless steel is widely used. It’s a great option for many applications because of these outstanding qualities. For instance, turbine parts, mechanical valves, medical equipment, and mechanical instruments.
Composition of Chemicals
With a composition of 11.5–18%, chromium is the essential component of martensitic steel, just like it is in all stainless steels. Nickel and carbon up to 0.75 percent are other prevalent components. Low nickel level restricts the corrosion resistance of martensitic stainless steel, however high carbon content gives it a robust molecular structure.
Stainless steel 410, 420, and 440 are the most prevalent varieties of martensitic stainless steel. The ultimate carbon content determines the maximum quenched hardness of these martensitic stainless steels, which behave similarly to high carbon steels during heat treatment processing.
Usually, a high temperature followed by quick cooling is used to harden martensitic. The term “air hardening” refers to the extremely high hardenability of martensitic steel. Since as-hardened martensitic has a very brittle structure, further processing is necessary to meet the needs of various applications.
To alleviate the microstructural stress, reheat materials at low temperatures.
Reheat at a slightly higher temperature to raise the hardness to an intermediate level.
Heating just below the critical temperature is the annealing process.
Complete annealing involves heating slightly over the critical temperature and cooling more slowly.
410 stainless steel
Stainless steel 410 is a general-purpose martensitic steel, and minor changes in hardening and tempering can alter its hardness level.
420 stainless steel
Stainless steel 420 has a comparatively broad range of hardness in both hardening and tempering settings because its carbon content ranges from 0.15% to 0.45%. HRC 40–50 can be reached by hardening this steel. Because of its versatile hardness, SS 420 is preferred for tempered goods in particular applications.
440 stainless steel
Compared to 410 and 420, stainless steel 440 may harden more readily, but its formability is limited during the annealing process. Because it can be hardened over HRC 50, this grade steel is desirable for use in blade applications. Blades with a higher hardness stay sharper for longer.
Martensitic Steel’s Properties
Because of their many properties, martensitic steels can withstand relatively moderate corrosive environments while maintaining their full strength and stiffness. The best forming properties are found in annealed martensitic steels, and hardening procedures are often carried out after forming operations.
Weldability
Typically, martensitic stainless steel is brittle, and most steels react negatively to welding. Additional quenching and tempering can also boost applicability and reduce brittleness. In contrast to stainless steel 410, which can be welded rather easily, high carbon martensitic steel is not appropriate for welding.
An attraction
The majority of martensitic stainless steels exhibit magnetic properties, which remain stable in both annealed and hardened conditions.
Formability.
Because the carbon content of stainless steel 420 ranges from 0.15% to 0.45%, it has a comparatively broad range of hardness under both hardening and tempering conditions. HRC 40–50 is the hardness range for this steel. For certain applications, SS 420’s versatile hardness makes it a viable material for tempered goods.
High Power
Components with superior mechanical qualities are the main application for martensitic stainless steels. The degree of corrosion resistance also restricts the range of uses when compared to other stainless steels. Often, the surfaces have some surface-level rust stains. Annealing circumstances might result in limited corrosion resistance, whereas hardening or tempering conditions yield the maximum corrosion resistance.
Martensitic Stainless Steel Hardening Process
One particular benefit of martensitic stainless steels is that they get stronger and harder after being heated. The typical techniques for hardening martensitic stainless steels to make them stronger.
Hardening with Age
By using heat to create precipitates, this process hardens steels and stops molecular structural defects from moving. Steels become stronger and harder due to all of these confinement flaws. Parts should be heated and then kept at a high temperature until the operation is finished.
Annealing
By heating steel, annealing can reduce tension and provide a homogenous molecular structure. As a result, the steels become softer and more manageable.
Tempering and Quenching
The process of quenching and tempering steels involves a number of intricate phases, including heating them, quickly cooling them, and then heating them once more. The steels are hard yet extremely fragile following the first heating and cooling processes. The steel will return to its ductile state after the second heating.
Applications of MIM 420
Surgical and medical
Because of its exceptional corrosion resistance and high hardness, MIM 420 is a sought-after material for parts like locking articulation bars. Cost-effective tooling design and fabrication in mass production are made possible by advanced MIM technology.
High-precision motion systems with tiny, complicated parts—which typically have complex structures and high tolerances—are necessary for robotic surgical systems. in order to offer improved motion, increased visibility, and a high degree of precision.
The Aerospace
Different nozzles can be connected to a field system using valve nozzle adapters; different adapter versions can support varied nozzle sizes and geometries. These adapters are ideal for stainless steel 420 because of its exceptional hardness and resistance to corrosion.
With substantial size molds, we can manufacture millions of components in the MIM sector. Compared to a traditional production technique, this lowers the leading time and cost.
Manufacturing in large quantities
The intricate features of screw extruder parts with spline need to be tailored for various mixing ingredients. Advanced machining techniques, various setups, and bespoke fixtures are necessary for conventional manufacturing.
Important characteristics of MIM stainless steel 420 for screw extruder components include high strength and hardness following heat treatments. in order to guarantee the materials’ long-term use and appropriate hardness during extrusion.
In conclusion
High strength, hardness, and resistance to corrosion are all good qualities offered by stainless steel 420. It is frequently used in applications using stainless steel.
Chemical Content
- 420
- 316L
- 304
- 440C
- 17-4PH
420 | C | Si | S | P | Mn | Cr | Ni |
w.t/% | 0.16-0.25 | ≤1.00 | ≤0.03 | ≤0.04 | ≤1.0 | 12.0-14.0 | ≤0.75 |
420 | Finished product density | Injection density | Hardness | Hardness after heat treatment | Tensile strength | yield strength |
7.25-7.3 | 4.66-4.70 | ≥320 | ≥460 | ≥1600Mpa | ≥1300Mpa |
316L | C | Si | S | P | Mn | Cr | Ni | Mo | N |
w.t/% | 0.03 | 0.75 | 0.03 | 0.045 | 2 | 16-18 | 10-14 | 2-3 | 0.1 |
316L | Finished product density | Injection density | Hardness | Hardness after heat treatment | Tensile strength | yield strength |
7.88-7.90 | 5.40-5.50 | ≥HV130 | / | ≥514Mpa | ≥180Mpa |
304 | C | Si | S | P | Mn | Cr | Ni | Fe |
w.t/% | ≤0.03 | ≤1.00 | ≤0.03 | ≤0.03 | ≤2.0 | 18.0-20.0 | 8.0-11.0 | Bal |
440C | C | Si | S | P | Mn | Cr | Ni |
w.t/% | 0.95-1.20 | ≤1.00 | ≤0.03 | ≤0.035 | ≤1.0 | 16.0-18.0 | ≤0.60 |
17-4PH | C | Si | S | P | Mn | Cr | Ni | Nb+Ta |
w.t/% | ≤0.07 | ≤1.00 | ≤0.03 | ≤0.04 | ≤1.0 | 15.5-17.5 | 3.0-5.0 | 0.15-0.45 |
17-4PH | Finished product density | Injection density | Hardness | Hardness after heat treatment | Tensile strength | yield strength |
7.56-7.60 | 5.38-5.50 | HV260-340 | ≥550 | ≥950Mpa | ≥660Mpa |