What is Australia Grade 250 mild steel?

00Ni18CO8MO5Tial martensitic aging steel is an ultra-high strength steel that uses carbon-free or ultra-low carbon Fe-Ni martensitic as the matrix and is precipitated and hardened by intermetallic compounds after aging treatment. The strength of this type of steel does not come from carbon, but from the precipitation of intermetallic compounds.

<> performance characteristics. Shanghai Bingzheng Industrial 18Ni steel solid solution after the formation of ultra-low carbon martensite, hardness of 28 30HRC, after aging treatment, due to the dissolution and precipitation of various types of intermetallic compounds to obtain aging hardening, the hardness can rise to the steel The outstanding feature is that it still has good toughness and high fracture toughness under the conditions of ultra-high strength and high hardness. At the same time, this kind of steel has no cold work hardening, small aging heat treatment deformation, good welding performance, and the surface can also be nitrided.

Shanghai Bingzheng Industrial 18Ni martensitic aging steel has high strength and hardness (ultra-high tensile strength, surface hardness 50 54HRC), good toughness and plasticity, is a key material for the manufacture of aerospace and defense industry equipment, and has been widely used in aviation, aerospace, precision molds and other industrial fields, and is currently widely used at home and abroad as a material for manufacturing high-precision load-bearing parts such as rocket engine shells, missile shells, uranium isotope centrifugal separators, high-speed rotating drums, etc.

18Ni (250) is a typical martensitic aging steel, which is an age-hardening plastic mold steel, with low carbon content in the steel, and is an alloy Ti, Al, Co, and Mo that play a role in age-hardening. Impurities have a great influence on the properties of martensitic age-hardened steels, and have a more obvious effect on steels with higher yield strength. This requires the steel to be smelted in vacuum to reduce impurities, segregation and gas content in the ingots to ensure that the steel has good toughness and fatigue resistance.

18Ni(250) Chemical Composition:

c≤ni17-19

p≤s≤si≤mn≤

18Ni (250) Mechanical Properties:

Solution temperature: 815-830

Aging temperature: 480 5

Hardness after aging: HRC50-52

Tensile strength: 1850

Yield Strength: 1800

Elongation after break: 10-12

Section shrinkage: 48-58

This is the Australian standard AS NZS 3678

Structural steels that require carbon equivalent have high requirements for strength and elongation.

Also, carbon equivalent.

It seems that there is production in China.

The silicon content of C250 is, whereas the silicon content of Q235 is< =, the silicon content exceeds the standard, and it cannot be fully corresponded.

All high-strength structural steel grade 250 should be the American standard.