30CrMnSi is a grade of alloy structural steel. Where "30" indicates an average carbon content of 0.3%, "Cr" represents chromium, "Mn" represents manganese, and "Si" refers to silicon. It is a high-strength quenched and tempered structural steel with a tendency to temper brittleness and poor transverse impact toughness, but good cutting performance, allowing manufacturers to easily process it into various precision parts. It has high strength and toughness, can withstand huge tension and pressure, and has good welding performance. However, when the thickness is greater than 3mm, it should be preheated to 150℃ and heat treated after welding. It is generally used after quenching and tempering.

Chemical element content (%)

Specification：2.00~42.00mm

Application: It is mostly used to manufacture various important parts with high load and high speed, such as gears, shafts, clutches, sprockets, grinding wheel shafts, bushings, bolts, nuts, etc. It is also used to manufacture wear-resistant parts with low working temperature, as well as variable load welding components, such as high-pressure blower blades, valve plates and non-corrosive pipes and tubes; widely used in automobiles, machinery, aerospace and other fields.

Mechanical properties:

-Tensile strength (σb) ≥ 1100MPa;

-Yield strength (σs) ≥ 800MPa;

-Elongation after fracture (δ5) ≥ 10%;

-Shrinkage rate (ψ) ≥ 45%;

-Impact absorption energy (Aku2) ≥ 50J;

-Brinell hardness (HBS100/3000, annealed or high temperature tempered state) ≤ 229.

It should be noted that the specific performance may vary due to different actual production and processing processes.

Heat treatment specifications:

-Quenching heating temperature: 880℃, coolant is oil;

-Tempering heating temperature: 520℃, coolant is water or oil.