How to choose plastic mold steel
selection of plastic die steel should be based on the type of plastic that is molded,
the shape, size, precision and quality of plastic products that are molded
and quantity of different requirements, at the same time to consider the
manufacturing mold conditions and processing methods, the selection of
different types of steel, such as seepage
steel, quenching and tempering steel, high carbon tool steel, corrosion
resistant steel, low carbon maraging steel, etc
.how to choose plastic mold steel - carburizing steel
carbon content of the carburizing steel is generally within the range of
0.1%~0.25%, and the hardness of the annealing state is low, and it has good
plasticity, can be made by cold extrusion molding method.Carburizing after quenching, low temperature tempering
treatment, die surface with
high hardness, high wear resistance and polishing, and a certain strength and
toughness, so as to ensure the use of the mold and effective
improve the service life of the mold.Due to the
carburizing steel has carbon low carbon steel 10, 20 steel and alloy low carbon
steel 20Cr, 12CrNi2, 12CrNi3A, etc.
Because of its poor hardenability, carbon low carbon steel is
only suitable for the mold with small load and low requirement.Low carbon alloy
Compared with carbon low carbon steel, steel has better
hardenability, so it is suitable for making plastic molds with larger sections
and larger loads.
Due to the limitation of long cycle, carburizing equipment and
batch, the use of carburizing steel is seldom used.
2.How to choose plastic mold steel - tempered steel
The quenching and tempering steel used for the plastic mold is
medium carbon steel such as 45, 55 steel and carbon steel and 4Cr, 3Cr2Mo,
4Cr5, MoSIN1 and other alloy steels.
Plastic molds are made from tempered and tempered steel, roughed
in the annealed state, then tempered and tempered, and finally finished.
Or after quenching and tempering or normalizing treatment,
direct rough machining and finishing, to avoid or reduce the deformation of the
mold during heat treatment
And cracks and other defects.
Carbon quenched and tempered steel 45 is a commonly used plastic
die steel, has good cutting performance, but because of its poor hardenability,
After the strength and hardness is low, the more suitable
hardness is HRC33~38, so it is only suitable for small or small batch
production of plastics
For the production of plastic products in large batch, complex
cavity of medium or large plastic mold, it is appropriate to use alloy tempered
The hardness of class steel is HRC42~48 after pre - hardening
3.How to choose plastic mold steel - high carbon tool steel
High carbon tool steels, such as Cr12, Cr12MoV, Cr WMn, 9Mn2V,
etc. have high hardness after quenching and tempering at low temperature
And high wear resistance.Therefore,
it is often used in the manufacture of thermosetting plastic molds or
wear-resistant thermoplastics (such as thermoplastics reinforced by glass
fiber) molds.The suitable hardness of this
kind of steel after heat treatment is HRC58~60.
4.How to choose plastic mould steel - corrosion resistant steel
Corrosion resistance of corrosion resistant steel is mainly
related to its chemical composition. Corrosion resistant steel is basically a
stainless steel with high chromium content.With
The surface of the etched steel processing die need not be
chrome plated.The commonly used corrosion
resistant steel is 4Cr13, 9Cr18, 9CrL8MoV, Cr14Mo,
Cr14Mo4V martensitic stainless steel.
5.How to choose plastic mold steel - maraging steel
Maraging steels are ultra-low carbon and ultra-high strength
steels.Ultra-low carbon maraging steel
has good workability, weldability,
Corrosion resistance and mirror processability.The hardness of maraging steel in solution state is HRC30~35,
and aged at 480℃ for
After aging, the hardness can reach above HRC50 and the
deformation is very small during aging.Therefore,
maraging steels are used
In order to obtain the required hardness and strength of the
mould, the mould can be made by mechanical processing in the state of solid
solution and then aging treatment
Degrees.Maraging steel is suitable for
the manufacture of large and complex plastic molds with high precision, wear
resistance and corrosion resistance.