38.10mm(1.5"), Large Solid Stainless Steel Metal Ball For Bearing

Introduction

Stainless steel balls are usually produced through a stainless steel forging process. At present, the commonly used stainless steel balls are 201, 302, 304, 316, 316L, 420, 440C.

According to the organization state, stainless steel is usually divided into martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel. In addition, according to the composition can be divided into: chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel and so on.

-Austenitic grade (300 series) is the most corrosion-resistant stainless steel grade. It is recommended to use forged solid/hollow ground stainless steel balls as bearings
When there is food contact. They are not ferromagnetic or ferromagnetic. They are not hardened.
-Martensitic grades (400 series) have corrosion resistance and high hardness. These grades are ferromagnetic. Forged solid/hollow ground stainless steel balls for bearings
They are mainly used where hardness, strength and wear resistance are required.
-Ferrite grades are ferromagnetic, but cannot be hardened or strengthened by heat treatment. They are more corrosion resistant than martensitic stainless steels, but not as good as austenitic stainless steels.

Heat resisting austenitic stainless steels

Heat resisting grades can be used at elevated temperatures, usually above 600 °C.

They must resist corrosion (usually oxidation) and retain mechanical properties, mostly strength (yield stress) and creep resistance.

Corrosion resistance is mostly provided by chromium, with additions of silicon and/or aluminium. Nickel does not resist well in sulphur containing environments. This is usually taken care of by adding more Si and Al which form very stable oxides. Rare earth elements such as cerium increase the stability of the oxide film.

Note: ferritic stainless steels do not retain strength at elevated temperatures and are not used when strength is required.

Austenitic stainless steel can be tested by nondestructive testing using the dye penetrant inspection method but not the magnetic particle inspection method. Eddy-current testing may also be used.

The relationship between the main chemical composition and the performance of stainless steel.

1. Carbon can increase hardness and strength, high content will reduce its ductility and corrosion resistance

2. Chromium can increase corrosion resistance, oxidation resistance, refine the grain, increase strength, hardness and wear resistance

3. Nickel can increase high temperature strength, corrosion resistance, and reduce the rate of cold work hardening

4. Molybdenum increases strength and has excellent corrosion resistance to oxides and seawater

5. Copper is good for cold forming and reduces magnetic properties

6. Mn is mainly used to reduce the magnetic properties of the material, but the content should not be too high.