JPS58181850A - Alloyed tool steel for plastic molding machine - Google Patents

Abstract

PURPOSE:To provide the titled alloyed tool steel capable of being made excellent in corosion resistance and anti-wear property, obtained by limiting a componential composition of C, Si, Mn, Ni, Cr, Mo, V and Co. CONSTITUTION:Alloyed tool steel contains, on the basis of wt., 1.3-1.8% C, 0.3-1.0% Si, 1.0% or less Mn, 0.5-4.0% Ni, 10.0-18.0% Cr, 0.4-3.0% Mo, 1.0% or less V, 2.0% or less Co, according to circumstances, 2.0% or less Cu and/ or 1.0% or less Nb and comprises the remainder Fe and a slight amount of impurities. This tool steel is suitable for parts used in a molding machine for molding, especially, fire sretardant resin or resin required in corrosion resistance and anti-wear property such as FRP. In addition, this steel can be provided with sufficient corrosion resistance and anti-wear property by containing Cr, Co, Ni in martensite having sufficient hardness in a solid solution form and dispersing carbide in a matrix after hardening and tempring.

Description

[Detailed Description of the Invention] Corrosion and abrasion resistance tII such as fiber-containing Libra Snack resin such as Yagarasu! The present invention relates to an alloy tool steel having excellent corrosion resistance and wear resistance suitable for parts used in 8M forming machines.

Conventionally, the parts of such Glasstech [1l1] molding machines were made of medium carbon steel such as SCMq HiroO.

A nitrided material such as SAcMi DaS that has been subjected to surface treatment such as chromium-saving plating or nitriding treatment is mainly used. However, these 11-sided treated steels had problems such as peeling off of the surface treatment layer during use, and unsatisfactory hardening of the hardened layer during processing due to distortion caused by heat treatment.

Moreover, once the base material is exposed due to localized wear or corrosion, it rapidly deteriorates in corrosion resistance and becomes unusable. In addition, as a V alloy tool steel to deal with these heel points, high carbon cold work tool steel has recently been known from Japanese Publication No. ShojA-301 and Japanese Patent Publication No. 88j&-,3,31134. -J-/0.0-Co
and, in some cases, further add Cu o, 4
Alloy steels containing 1 and 0 carbon atoms have been produced, but these steels are difficult to hot forge, have poor machinability, and have a high Co content. Economically, there is also time. On the other hand, Tokukai Akira! An alloy tool steel containing only 7% carbon fi1kO,j~/, has been announced in Publication No. 4 of Dar//jA/4, but this steel has few carbide cliffs due to its low carbon content; Moreover, it has poor abrasion resistance.

Therefore, the present invention solves the above-mentioned drawbacks of the conventionally known all-metal molding tools and provides a combination tool that can satisfy all of the current requirements. One of the objectives of this research is to obtain an alloy tool steel suitable for use.

In order to achieve this objective, the alloy fabrication A11llll according to the present invention has been developed by weight - C1,3 ~/, 1 whisper, S10, J
~/, 0%, Mn/, D% or less, N1θ,
j ~ q,.

%, Cr/θ, 0~/g, θ attack, Mo O,'l~3
．． 0%, v/, 0% or less, Co 2.0% or less, others, Cu 2. θ whisper or less and (or)
It is characterized in that it contains all Nb/, less than 0 whisper, and the remainder consists of Fe.

Hereinafter, the present invention will be described in detail based on the attached document containing examples and test results thereof.

The alloy l&steel according to the present invention is characterized by having the chemical composition as described above.

After quenching and tempering, this steel has 1# of elements such as Cr%Mo, Co and N1 as a matrix in the martensitic structure with sufficient hardness, and at the same time, carbides (Cr, Mo,
By dispersing V, Nb, etc. in one base, sufficient corrosion resistance and wear resistance can be provided.

First, the selection of each chemical component and the reason for limiting its range in the alloy tool steel according to the present invention as described above will be explained.
It is as follows.

C is an important element to increase the hardness of the Zenmetal I & Steel of the present invention, and in order to obtain a hardness of HRCA 0 or more, /, 3 whispers or more is required, but /, l- Exceeding this is not preferable because the hardness will be saturated and corrosion resistance will deteriorate, and toughness, forgeability, and machinability will deteriorate.
The upper limit is 8g%.

Sl is usually used as a deoxidizing agent, but /
It is not preferable to contain more than 20% of the content because the toughness will decrease. Therefore, l17. ．． 7~8! - limited to.

Mη is added as an AM agent, and if it is added in an amount of 1 or more, retained austenite will be generated and the quenching hardness will be reduced, which is not preferable. Therefore, it is limited to /, 0 whisper or less.

Ni
Halogen such as HBr; increases corrosion resistance against IA acid, but if it exceeds θ%, the quenching and tempering process will result in a large amount of retained austenite (and the hardness will decrease, so O,S% or more) limited to 0% or less.

Cr is an effective alloying element against corrosion of plastics, and 70% or more of Cr is required to provide corrosion resistance. On the other hand, Cr combines with carbon to form carbide, and this carbide is effective for wear resistance, and 10% or more is required. However, cr/
If the Lθ temperature is exceeded, residual otenite will significantly occur during quenching and tempering, and the hardness will decrease. θ〜i
limited to g, o-.

Mo is a carbide forming agent and increases temper softening resistance. It also increases corrosion resistance to plastics. However, 0. *Below @, the effect is not obvious (, J, above 0%.

Since carbides precipitate in large numbers and corrosion resistance deteriorates, the content is limited to 0.0% to 3.0%.

(2) is a strong swelling-forming element and contributes to improving wear resistance. However, if you go beyond /chiwo.

Forgeability becomes hot and grindability is impaired, so tll below /chi! despise.

Co is an extremely effective element for corrosion resistance,
It also *contributes to improving the return hardness. However, if it exceeds -%, forgeability deteriorates and machinability also deteriorates. Moreover, the toughness also deteriorates.

Economically, the m-grade is higher, so it is limited to J, 094 and above.

CU is added to the matrix and improves corrosion resistance. However, if it exceeds 2.0%f, hot workability will be impaired, so it is limited to 04 or below.

Nt) is a powerful carbonization element and contributes to improving wear resistance. Further, by adding this element, it is effective in making carbides finer.

Shiri・shi, /, θ whisper [If it exceeds, the forgeability will deteriorate and the grindability will be impaired, so limit it to /, 0 whisper or less.

Next, the present invention will be explained in detail.

The table shows the composition (weight %), aging conditions, and hardness of the conventional alloy steel and the example of the present invention, respectively. In addition, 80M4Ieθ and SACM61I5j11 were adopted as conventional alloy steels, and SS4'/ was adopted as a comparison.On the other hand, as an example of the invention steel, basic alloy steels were used within the limited range of each component in this Those with different ingredients were named A7-6.

Abrasion tests were conducted on these test materials! The result of the meeting p
l. In Figure 7, am<wear loss (gr/dm')r,
This wear test was carried out using a rotary sand abrasion tester as schematically shown in Figures 1 and 3. However, this #iso is a cylindrical 6 basin / with silver sand.
A single trochanter J is arranged horizontally in this silver sand L so that it can be rotated once, and it is driven once by a motor with a decoupling mechanism installed on the top of this trochanter Jtll device/. The test is carried out by applying 1 in the radial direction to the dovetail of the rotor 3.
Iil & test piece ji installation, water wft on the top surface of the sand
The rotor 3 was rotated once by the motor while being injected and overflowed, and the test piece J was abraded by polishing with silver sand.

In addition, Fig. 1154I shows the results of a corrosion test conducted by immersing the sample material in highly corrosive ABS-based M resin in order to test the corrosion resistance of the plastic plate.
m', Hr).

First, from the results of the wear test shown in FIG.
A/~Meng is the conventional JIssCM41uO and JIS
SACM! than those that have undergone s t* processing.

It is clear that the amount of wear is small and the wear resistance is good. Furthermore, from the results of the corrosion test shown in FIG. 9, it is clearly recognized that the present Ji#IA*A/~4 has less corrosion and longer corrosion resistance than these conventional steels.

As described above, the joint tool steel according to the present invention has excellent both wear resistance and corrosion resistance, and it is clear from the fact that it showed good results in the ABS resin immersion corrosion test.・As mentioned above, especially.

Alloy processing x, 1IIIYka, which is most suitable for each part of plastic snack molding machine! It is something that can be provided.

[Brief explanation of the drawing]

Figure 7 shows the wear demagnetization of the inventive alloy and the comparative alloy, and the time 1
ml, Figure 1 is a vertical cross-sectional diagram showing the depth of the abrasion charge IR, Figure 3 is a flat diagram of the pipe, and Figure 9 is a diagram showing the relationship between the alloy of the present invention and A13s with comparison alloy, 1%
Result of immersion corrosion test in resin (f-boss diagram). Applicant: 2&A #1 company Applicant: Mibishi Heavy Industries Co., Ltd. Agent: Teru So Ga Michi 244- Procedural amendment January J7, 1945, Mr. Commissioner of the Japan Patent Office, 1, Indication of the case, Showa Itsu, Patent Application No. 6 Dak J/No. 2, Title of the invention, Plastera I Weikenki Yong Kaikin Tool Steel, 3, Person making amendment case Relationship with Patent Applicant (Mitsubishi Heavy Industries, Ltd. 4, Agent 5, Subject of Supplement a) Column (2) of most of the details of the specification (2) 1III One of the statements in the main specification The part is corrected as follows, and Figures 1 and 9 are corrected as shown in the attached No. 1 and Guess.
IS8C+, j 4Il OJ and line 79 [SAC
M 44 t, 1 r JISSAOM A 413
Correct it with J. Yu Page 7 #! Row [ECM q y o and SA
CMAfjJ ryxsscMq IIo and JIS
SACMA41jJ and 1st O line [5SII/j
[JIsEIs4I/and JISSKD//
Correct it with J. 3 Page 9, line 11 [Replace JISSCM 440 J with “JISSOM Q I/O, JISSKD / /
Correct it with J. Revise the table on page 7θ as shown in the attached sheet.

Claims (1)

[Claims] l Weight - C1,3~/, 1-81 0,3~/, 0% Blood Ha θ Ni O, 1 ~ Tei, Q Chron Cr / 0.0~/ 1. 0'f4Mo
An alloy tool steel for plastic fii and forming machines, characterized in that it contains 0.41 to J, 0% V/, 0 or less Co, O- or less, and the balance consists of F+s and some impurities. 210 with C7, 3~/, 1% Si 0.3~/, 0 whisper MQ/, 0% or less Ni O, 3~q, θ %Cr
/0.0~/g, 0%Mo
O, q~3.0 Whisper V/, 0
Less than a whisper CO2, 0% or less and CaJ, 0% or less and/or Nb/, 0%
Including the following and the rest? , and some impurities.