JPS60162590A - High-hardness build-up welding material - Google Patents

Abstract

PURPOSE:To provide excellent resistance to cracking and wear and attain high hardness by specifying the compsn. of a build-up welding material. CONSTITUTION:A high-hardness build-up welding material is formed of the compsn. contg., by weight %, 0.5-1.5% C, <=0.5% Si, 0.8-2.0 Mn, 2.0-6.0% Cr, 6.5-10.0% Mo, 1.0-2.0% V, 2.0-6.0% CO and 1.0-3.0% W and consisting of the balance Fe and inevitable impurities. The good resistance to wear is thus obtd. and defects such as seizure, crack, etc. are eliminated.

Description

[Detailed description of the invention] The present invention relates to a high hardness overlay welding material.

In general, the durability of many mechanical parts used in industries such as steel, cement, mining, and civil engineering and construction is greatly affected by wear.

Today, in order to reduce costs in various places, methods are used to improve the durability of mechanical parts by overlaying wear-resistant materials on parts that wear out.

The present invention has a very high shear hardness of 9D, has excellent cracking resistance and wear resistance, and is subject to various rolls and rollers that require high hardness, intermetal wear, grinding wear, etc. The purpose is to provide a welding material that is suitable for hardfacing of mechanical parts and can significantly extend its service life.
, s% or less, Mu: α8-10%, Cr: 20-4
0%, MO: 6.5-10.0%, V:LO-2+o
%, (Q: 2.0 to eLO%, W: LO to ao%, and the remainder is Fe and unavoidable impurities.

The reasons for limiting the components of the overlay welding material of the present invention will be explained below. Note that all percentages hereinafter indicate weight percentages. CTC is an austenite-forming element and is dissolved in the matrix,
It also forms carbides with Crs Mo, V, W, etc., improving wear resistance.

A content of 2.0% or more lowers the toughness of the weld metal and causes hot cracking during welding.

If the content is less than 0.5%, the specified hardness cannot be obtained and the l9 resistance
! Abrasion resistance is reduced.

Si: Si is effective in deoxidizing the weld metal and preventing inclusion of intervening impurities in the welded part, but if it is contained in an amount of α5% or more, it reduces the toughness of the weld metal and causes cracks.

Mn: Mn is effective in deoxidizing the weld metal and preventing the inclusion of impurities in the weld zone, but if it is present in amounts of 20% or more, it causes excessive deoxidation and coarsening of the particles, resulting in poor wear resistance and Decreases corrosion resistance. If the content is less than 0.8%, deoxidation will be insufficient and pits, blowholes, etc. will occur.

Cr: Cr combines with C to form carbide, which is essential for improving IF wear resistance. However, since Cr is a ferrite-forming element, its content in an amount of &o% or more lowers hardness and causes bead marks and the like.

If the content is less than 20%, the desired hardness cannot be obtained and the wear resistance decreases.

Mo: Mo improves heat resistance, corrosion resistance, and abrasion resistance, and is self-sufficient. If the content is less than 6.5%, the hardening ability is insufficient, the desired hardness cannot be obtained, and the abrasion resistance decreases.

Moreover, the effect of preventing high temperature embrittlement is reduced.

v: ■ Together with Mo, it is effective in improving heat resistance, corrosion resistance, abrasion resistance, and self-hardening properties, but when it is contained in an amount of 20% or more, self-hardening properties are significantly reduced. This is because the solid solution rate of V carbides is slow and the structure itself obtained by the growth of fine carbides reduces hardenability. In addition, welding workability is deteriorated, such as slag peeling. If the content is less than 1.0%, sufficient toughness will not be obtained and crater cracks will occur.

Co: Co is effective in improving self-hardness, coexists with Mo1VsW, etc., and greatly increases hardness and wear resistance. A content of more than aO% is uneconomical, and the curing ability is insufficient compared to an I content of 20% or less.

WOW is an essential element for horses that increases hardness.
In combination with Mos V%Co etc., the hardening ability is greatly increased. If the content is 10% or more, a large amount of carbide will be formed.
Toughness decreases and cracks occur.

If the content is 1.0% or less, the curing ability is insufficient.

The reason for limiting the components of the overlay welding material of the present invention has been explained above, but the specified target performance is not obtained only by the effect of a single element, but by the synergistic effect of a combination of various elements. .

The overlay welding material of the present invention includes a covered arc welding method, a submerged arc welding method, a gal-shielded arc welding method, and a self-shielded arc welding method. Next, an example will be described.

<Example 1> A leveler roll in a steel industry cold rolling facility in which submerged arc welding of the overlay welding material of the present invention was performed on a base material of S to 35c to a thickness of 8 pieces with a thickness of 6 pieces was used. -2 with surface hardening was used, but the surface abrasion was 1
The wear resistance was 1511 JI per month, but extremely good wear resistance was obtained, with ◎-11 U per month.

Furthermore, there were no defects such as seizures or cracks, and the surface hardness after 6 months of use was the same as before use.

<Example 2> A striking plate for crushing coal, limestone, stone, brick, coke in the cement manufacturing industry, quarrying industry, ceramic industry, iron manufacturing industry, etc.
The first coated arc welding method using the welding material of the present invention for impact blades
Overlay construction was carried out as shown in Figures 2 and 2. Figure 1 shows an impact blade for crushing coke in the steel industry;
As shown in FIG. 1, a weld overlay (2) was applied to the No. 41 base metal (1) using a high carbon, high chromium welding rod (3% by weight of C, 2 & 7% by weight of Cr).

However, as a result of conducting covered arc welding using the welding material of the present invention in the same manner as shown in Figure 1, the durability was 10 weeks compared to the 3 weeks of the conventional product, which is more than three times better. This was the result. Furthermore, no missing build-up parts due to cracking were observed.

Figure 2 shows a striking plate for crushing limestone in the cement manufacturing industry. Conventionally, SCMnHu type was used, but SS
-41 base metal (1) As shown in Figure 2, the overlay metal (2) is formed by covered arc welding using the overlay welding material of the present invention, whereas the conventional one has a durability of one month. However, good results were obtained, with a durability of 2 months, which is twice as long.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an impact blade for crushing coke in a steel manufacturing industry, and Fig. 2 is a perspective view of an impact plate for crushing limestone in a cement manufacturing industry. Fig. (1): Base material (2): Overlay metal patent applicant: Fuji Kogyo Co., Ltd. Representative: Noriyoshi Ariyoshi Toki No. tfjA Fig. 2

Claims (1)

[Claims] 1) In weight%, C: 0.5 to L5%, Si: a5
% or less, Mn: 0.8~zo%, Cr: zo~s,
o%, Mo: &5-w1O, o%, V: 1.0
~2+0%, Co:2o~ao%, W:1.0~3.0
%, with the balance consisting of Fe and unavoidable impurities.