JPS6389638A - Electrode material for spark plug - Google Patents

Abstract

PURPOSE:To develop an electrode material excellent in lead attack resistance, by regulating respective contents of Si, Cr, Mn, etc., in an Ni alloy as an electrode material for spark plug and also by adding and incorporating specific amounts of Al. CONSTITUTION:As the electrode material for spark plug in a engine using leaded gasoline, an Ni-base alloy containing, by weight, 1.3-1.7% Si, 1.3-1.7% Cr, 1.2-1.6% Al, <0.4% Mn, and <0.05% C is used. In this way, the Ni-base alloy as electrode material for spark plug excellent in lead attach resistance can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrode material for a spark plug, and particularly to an electrode material having excellent lead attack resistance.

[Conventional technology and its problems]

As electrode materials for spark plugs, Ni, Sis Cr,
Ni-based alloys to which one or more types of Mn or the like are added in an amount of about 1 to 10% by weight are exclusively used.

This existing Ni-based alloy has sufficient durability under the conditions of boat fishing, but as engines become higher output and rotate at higher speeds, lead attack resistance has increased in engines that use leaded gasoline. There is a growing shortage of carbon fibers, and improving durability in this aspect is one of the challenges in this field.

Therefore, this invention aims at adding Si, Cr, Mn to Ni.
Adjust the amount of etc. and make a new A! By adding , the aim is to provide an electrode material with superior lead attack resistance compared to conventional materials.

[Means to achieve the purpose]

In order to improve lead attack resistance, this invention changed the composition of the electrode material to include 1.3 to 1.7% Si and 1% C by weight.
．． 3-1.7%, Al 1.2-1.6%,! 'In was 0.4% or less, C was 0.05% or less, and the remainder was essentially Ni, excluding impurities.

Si is an element added for the purpose of improving high temperature oxidation resistance and lead attack resistance, and in relation to the amount of other metal elements added, its content is 1.3% by weight or less, especially 1. If it is less than 1.7% by weight, the effect will be small, while if it exceeds 1.7% by weight, particularly cold workability will deteriorate.

Therefore, the amount of 5i added is limited to 1.3 to 1.7% by weight.

Cr is also an element that improves high-temperature oxidation resistance and lead attack resistance in the material of this invention, but due to its relationship with other additives, if it is less than 1.3% by weight, it has little effect. On the other hand, if it exceeds 1.7% by weight, cold workability will particularly deteriorate. Therefore, the amount added is limited to 1.3 to 1.7% by weight.

Like Si and Cr, AI is an element that improves high temperature oxidation resistance and lead attack resistance in the material of this invention.

This Al is added in an amount of 1.2% by weight or less, especially 1% by weight.
If the amount is less than 1.6% by weight, the effect will be small, and if it is 1.6% by weight or more, especially 2.0% by weight or more, cold workability will be particularly deteriorated like the former two elements, so the amount should be 1.2 to 1.2%. The amount is 1.6% by weight.

Mn is added as a deoxidizing additive in the present invention, but if the amount exceeds 0.4% by weight, the cold workability will particularly deteriorate, so the amount is set to 0.4% by weight or less.

Furthermore, if C exceeds 0.05% by weight, the cold workability will deteriorate, so the content should be 0.05% by weight or less.

〔Example〕

Examples will be described below. Table 1 shows the components and amounts added to Ni for the electrode material of the present invention, comparative materials and conventional electrode materials in which the amount of each element added is outside the scope of the present invention. I'hl, -2 is the electrode material of the present invention, 3 to 12 are comparative materials, and 1lh13 is a conventional material.

Table 2 shows the evaluation results of lead attack resistance, high temperature oxidation resistance, and processing load for each material in Table 1.

Table 1 Table 2 Sparrow Lead attack resistance: Dangen: Base material survival rate after holding fish 'cx for 2 hours in a mixed bath of PbS-1:1 Roasted high temperature oxidation resistance: 1000t x 4 minutes ω'cx
Base material survival rate after repeating Z minutes of thermal cycles < Processing load: From Table 2 on the load required for extrusion molding,
The 7% polar material (fish Llh2) of this invention is different from the conventional material (m1
Although it is inferior to 3) in processing load, it is slightly superior in high temperature oxidation resistance, and it can be seen that lead attack resistance has improved by more than 40%.

In addition, from the evaluation results of comparative materials of Kan 3 to Magnetic 9, Si, Cr
It can be seen that when the content of any one of 5Att is small, the lead attack resistance is particularly deteriorated. Furthermore, 1lk1.10~
From the evaluation results of the comparative material of Magnetic No. 12, it can be seen that as the content of each additive element increases, the workability deteriorates significantly.

〔effect〕

As is clear from the above examples, Si, Cr and Ni
, AI, M11% According to this invention in which the amount of C added is specified, a remarkable improvement effect on lead attack resistance can be obtained,
Even when used in spark plug electrodes for engines that use leaded fuel, it can exhibit sufficient durability.

Claims (1)

[Claims] The weight ratio of Si is 1.3 to 1.7%, and Cr is 1.3 to 1.7%.
7%, Al1.2-1.6%, Mn 0.4% or less, C
An electrode material for a spark plug, characterized in that the electrode material contains 0.05% or less of Ni, and the remainder consists essentially of Ni excluding impurities.