JPS613869A - Knockout pin for reinforced plastic having superior toughness - Google Patents

Abstract

PURPOSE:To manufacture a knockout pin for glass fiber reinforced plastics having superior toughness and causing no breaking during use by using a Cr-Mo steel having a specified composition. CONSTITUTION:The knockout pin for a molding apparatus for reinforced plastic contg. glass fiber or metallic powder is made of a steel bar having a composition contg. 0.65-0.85% C, 0.10-0.50% Si, 0.10-0.60% Mn, 3.5-5.0% Cr, 3.0- 5.0% Mo and 0.6-1.4% V. The steel bar is worked into a prescribed shape, quenched from about 1,050 deg.C, and tempered at about 560 deg.C to manufacture said knockout pin. This pin has high toughness without breaking, and also has superior wear and seizing resistances. The dimensions are not changed even after long-period use.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an extrusion bottle for a reinforced plastic molding device.

As an extruded bottle for plastics, it must have sufficient toughness to avoid breakage during use, high wear resistance on the sliding surface, good seizure resistance, and dimensional change during long-term use. It is required that there be no.

Conventional general-purpose glass extrusion bottles are 8 to 8.2.
/ is quenched at approximately 3θ℃, then tempered at 7g0 to 200℃,
Products with hardness around HROAθ are widely used, but extrusion bottles made from 8 to 8.2 have the disadvantage that they expand after long-term use when the working temperature during plastic molding is around 200°C. In the case of oak or glass fiber-filled reinforced plastics, abrasion resistance is insufficient. Therefore, it is 8Kb// for reinforced plastic! 11! Extrusion vinyl is used.

8KD / / manufactured by extrusion piping / has very good wear resistance.

However, due to the lack of toughness, relatively small-diameter extrusion pins have the disadvantage of causing breakage during use.

The present invention has been made in view of these problems.
The purpose of this product is to provide an extrusion pin made of 8KD/ / which has excellent toughness, moderate abrasion resistance, and is suitable for reinforced plastics containing glass fiber, etc. .

That is, the present invention has a weight percentage of 0665 to 6 g, 5'chi, 8
iθ/~θ, 5%, Mnθ/~θotchi, Or 3 j
~j: θchi, Mod θ~jθchi, ■θ6~/, After processing a steel bar consisting of residual iron and some impurities into a predetermined shape, it is quenched at a temperature of about /θjθ℃. This is an extrusion bottle made of reinforced plastic with excellent toughness, which is characterized by having been subsequently tempered at a temperature of around 60°C, and is an extrusion bottle manufactured by SKD//.

It has extremely good toughness, and wear resistance is SKD.
Slightly inferior to I'/manufactured extrusion pin, 8KS2
/ Bottle making is much better. Furthermore, since the tempering temperature is as high as approximately 5°C, there is no dimensional change during use even at working temperatures of around 200°C. Therefore, the extrusion pin of the present invention is suitable for extrusion bottles for reinforced plastics containing glass fibers.

Next, the reasons for limiting the composition of the extrusion pin of the present invention will be described.

C increases the hardness of martensite, Or%Mo, V
However, if C is less than θ6S, the wear resistance will be insufficient, and if C is less than θ
If the toughness exceeds gs*, the toughness decreases, so
It was hot. Company 81 is added as a deoxidizing agent, but if it is less than θ/ls, its effect is small.

If it exceeds θj%, decarburization becomes easier, so θ/~.

It was limited to θS. Mn also has a deoxidizing effect, but if it is less than θ/h, the effect is small, and if it exceeds θ6%, there will be a lot of retained austenite during quenching, so it was set as θ/~θt.

Ar creates hard carbides, improves wear resistance, and increases hardenability, but if it is less than 35%, the effect is small;
Moreover, if i0%'e exceeds, the toughness decreases, so 1j-1
: θ is set.

MO thickens hardenability, increases temper softening resistance, and increases wear resistance, but its effect is small below 3θ, and the improvement in effect is small even when it exceeds 50%. Mathechi Toshida. ■ also forms special carbides to improve wear resistance, but if it is less than θ6, the effect is less, and if it exceeds 77%, the toughness decreases, so θ6~/4t
limited to chi.

Hereinafter, the present invention will be specifically explained by referring to all embodiments. 1st
The table shows the chemical composition of the extrusion pin of the present invention and the conventional extrusion pin. In the table, symbol A is the extrusion pin according to the present invention, symbol B is SK
An extrusion pin made by D// is shown.

Table 2 shows the heat treatment applied to the φ/θ■ extrusion pin and the hardness of the heat treatment.

Table 2 Heat treatment hardness Table 3 shows the durability test results of φ/θ throat extrusion pins manufactured by applying the heat treatment shown in Table 2 to steel with the chemical composition shown in Table 1. be. That is, the graph shows the presence or absence of breakage of the /θ■ extrusion pin after /4θθθ shot, 34θθθ shot, and jθ, θθθ shot of reinforced plastic containing glass fiber.

Table 3 Ejector Pin Durability Test Results In sample B No. 8, the extrusion bottle made by D// broke after 3θ and θθθ shots, but the ejector pin according to the present invention
No breakage even after θ, θθθ shots.

It was confirmed that the material had excellent toughness, and at the same time, no abnormalities were observed in wear or dimensional changes.

As explained above, the extrusion pin of the present invention has Cθ
Zajchi, siθ/~θSchi, Mnθ/~θ6chi, 0r
31~i0%, MO, 3θ~, 5.0%, Vθ~/A steel consisting of mouth remainder iron and some impurities, approximately/
It is characterized by being quenched from θSθ℃ and tempered at around 568℃, and the 8KD// extrusion bottle also has extremely excellent toughness, so there are no breakage accidents during use. 6D, and also has moderate abrasion resistance, making it ideal as an extrusion pin for glass fiber-containing 9-carbon plastics.

Claims (1)

[Claims] In weight%, C0.65-0.85%, Si0.1-0.
5%, Mn0.1-0.6%, Cr3.5-5.0%,
After processing a steel bar consisting of Mo3.0~5.0%, V0.6~1.4% balance iron and some impurities into a predetermined shape, it is quenched at a temperature of about 1050°C and then heated to 560°C.
An extruded pin for reinforced plastics with excellent toughness, characterized by being tempered at temperatures around ℃.