410 Stainless Steel Round Bar

Is 410 Stainless Steel good？

410 Stainless Steel Material is a basic straight chromium high hardenability martensitic stainless steel with good strength and fairly good corrosion resistance, typically quenched and tempered in the tensile range of 700 -850 Mpa (Condition R) Brinell hardness range 201 -255. characterized by good corrosion resistance in mild environments atmospheric industrial and domestic environments, coupled with good strength and excellent toughness in quenched and tempered conditions. Good strength and excellent toughness. 410 Due to its excellent hardenability, it is capable of being fully hardened to Rc40 and above, depending on carbon content and section size. Smaller sections can be air cooled and larger sections can be oil quenched to maximize overall hardness. Prehardened and tempered 410 also readily responds to nitriding to achieve typical surface hardnesses in excess of Rc65. However, the nitriding process reduces corrosion resistance and is not normally recommended except in critical applications where the benefits outweigh all other considerations.

Material is magnetic under all conditions.

High Temperature Properties
410 exhibits good resistance to scaling in continuous use up to 650 o C. However, at these higher operating temperatures it results in a significant decrease in tensile strength and hardness, followed by an increase in ductility. However, use at these higher operating temperatures results in a significant decrease in tensile strength and hardness, followed by an increase in ductility.

Typical Mechanical Properties at High Temperatures, Hardened at 1010 o C and Tempered at 30 o C Above Operating Temperature
Caution.：Creep and stress fracture strengths are also greatly reduced at these higher operating temperatures.

Low Temperature Properties
410 is not recommended for use at sub-zero temperatures because of the significant reduction in impact properties consistent with most steels other han austenitic steel types.
Cold Bending
In the hardened and tempered condition, it is much more difficult because of the high yield strength that must be taken into account.
Hot bending
In the hardened and tempered state, it is not recommended because it affects the mechanical properties in the heat affected zone.
Corrosion resistance
The corrosion resistance of 410 is better than that of Grade 416, but lower than that of Grade 431. It is also lower than most 400 series ferritic stainless steels and all 300 series austenitic stainless steels.NB. It has its best corrosion resistance in the hardened and tempered condition and is therefore not recommended for use in the annealed condition. It is most important to always allow oxygen to circulate freely over all stainless steel surfaces to ensure that a chromium oxide film is always present to protect it. If this is not the case, it will rust like any other type of non-stainless steel. For optimum corrosion resistance, surfaces must be free of scale and foreign particles.
Finished parts should be passivated.

Forging
Heat evenly to 1100 o C -1200 o C, holding until the temperature is uniform throughout the part.
Do not soak but start forging immediately. Do not overheat as this will result in loss of toughness and ductility. Do not forge at 900o C. Finished forgings should be cooled slowly in ashes or warm dry lime, etc., until hand warm and annealed immediately.

Heat Treatment
Subcritical annealing
Heat uniformly to 650 o C -750 o C as required and hold until temperature is uniform throughout the part. *Soak as required and cool in air. Note: For best machinability, use the lower end of the range.
Annealing
Heat uniformly to 820 o C -900 o C, hold until temperature is uniform throughout the part. *Soak as required. Cool in furnace.
Hardening
Heat to 950 o C -1020 o C and hold until temperature is uniform throughout the part. *Soak as required. Harden in oil or air cooled. Temper immediately while hand warm.
Nitriding
Before nitriding, the chromium oxide film protecting the surface must be destroyed by pickling or fine sandblasting. Nitriding is carried out at 500 o C -550 o C, followed by slow cooling (without quenching) to minimize distortion problems. As a result, parts can be machined to near final dimensions, leaving only grinding tolerances. Always ensure that the tempering temperature used during the initial heat treatment is higher than the nitriding temperature, otherwise core strength will be compromised.

Tempering (Condition R)
Heat to 600 o C -700 o C as required, holding until the temperature is uniform throughout the part. *Soak as required. Cool in air. The following double tempering treatment is recommended for optimum toughness. Heat to 650oC - 680oC. *Soak as required. Cool in air.

Then:
Reheat to 620oC - 660oC. *Soak as required. Cool in air
410 It is certainly possible to temper at much lower temperatures, producing much higher tensile strength, but then with lower impact properties.
Note that tempering in the 400 o C -580 o C range should be avoided due to temper brittleness, which results in a significant reduction in impact properties and loss of corrosion resistance.
Heating temperatures, heating rates, cooling and homogenizing times will vary depending on factors such as the size/shape of the workpiece, type of furnace used, quenching medium and workpiece transfer equipment.

Machining
The 410 machine is best in the hardened and tempered condition R. It is considered easy to machine all operations such as turning, milling and reaming, being able to follow the machine tool builder's recommendations for suitable tool types, feeds and speeds. It is not as hardened as the 300 series austenitic stainless steels, but is more similar in this respect to low alloy high strength steels such as 4140.

Welding
Welding 410 requires special care in the quenched and tempered condition or in the annealed condition because of its air-hardening ability, which can lead to the formation of brittle martensite and cold cracking due to shrinkage stresses in the weld and heat affected zone. Welding in the annealed condition helps to accommodate some of these shrinkage stresses in the base material when highly constrained or large cross sections are applied. However, problems can still occur. The higher the carbon content and the higher the hardening capacity, the greater the risk of cracking. Preheating and interlayer temperature control during welding, combined with very slow cooling and post-weld annealing are the best ways to prevent cracking.