JPS58113355A - Body material - Google Patents

Abstract

PURPOSE:To obtain the body material of a metallic band saw with superior torsion fatigue characteristics and superior wear resistance by regulating the C content of a Cr-Mo-V steel having a specified composition to a relatively low value and the Cr content to a relatively high value or by further adding Nb, Ti and Ni. CONSTITUTION:This body material of a metallic band saw using a high speed steel as the edge material is a steel contg. 0.25-0.40% C, <1.50% Si, <1.50% Mn, 3.10-6.00% Cr, 0.30-1.50% Mo and 0.40-0.80% V or further contg. 0.02- 0.20% Nb and/or 0.02-0.20% Ti, and/or 0.1-1.5% Ni. This material has high torsion fatigue characteristics under repeatedly applied stress and superior wear resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a body material for a metal pantone whose blade material is made of high-speed steel and whose body portion is welded by various welding methods.

Many metal band saws are made by welding high-speed steel as a cutting edge material to a low-friction body material using an electron beam welding method, and then applying 75mm butt welding to make it endless. After the cutting edge is welded to the body material, it is quenched and tempered in order to obtain the necessary hardness, but since the quenching is carried out under the temperature conditions of high-speed tool steel, the temperature is high, such as 1150°C or higher. In general, metal band saw body materials are made of Al5I6150 or other alloys that have been added with Nb, Ti, etc. to suppress grain coarsening due to high temperature quenching, and other alloys that have various improvements in weldability. has been developed, and the present applicant previously filed Japanese Patent Application Laid-open No. 5@-102555 and Japanese Patent Application No. 56-135.
541 has been filed. On the other hand, endlessly connected metal pantones always require 4G'~ while cutting the material.
A torsion of so'@ degree is provided, and various stresses such as tension and cutting resistance necessary for cutting work are applied to it and work repeatedly. Under such stress conditions, said shell material:
It is not necessarily sufficient for fatigue properties. First, when cutting difficult-to-cut materials such as stainless steel, excessive stress is applied to the pantone, which causes the body to buckle and bend during cutting. Therefore, the present inventors conducted various research to develop a metal band saw body material that has high screw fatigue properties under reverse stress conditions and excellent wear resistance.As a result of various studies, the composition shown below is It has been found that a steel of

That is, the present invention provides CG, 25 to 0.40%, 811
．． 50Q, 30~1.50X, Vo, over 40~Q
, 80X and as necessary, 9 Nb0.02~0.20X,
It is a metal pantone body material containing one or two types of TiG, 02-0.20XO, and further contains NiQ, 1-1.5X if necessary, and the remainder is F and inevitable impurities. .

The above-mentioned material of the present invention has excellent multi-fatigue properties and fatigue resistance, and these properties are mainly 1csi, Me.

J) For steel containing Nb and TL, it is necessary to keep the KC content low (conventionally) and to increase the Cr content (conventionally). It was obtained by That is, V, Nb, and TI are used to prevent coarsening of crystal grains during high-temperature quenching, thereby obtaining a dense heat-treated structure.

Si, Cr, Mo, and V maintain high strength through secondary hardening during tempering. In particular, the reason for increasing the Cr content and keeping the C content to an appropriate level is that the 1150 to 125
When high-temperature quenching at 0'C is performed, C in the steel matrices and steel tends to precipitate and agglomerate, resulting in a decrease in toughness and torsion fatigue properties.

However, since Cr is difficult to aggregate, it is possible to improve the toughness without degrading it. However, if the content of MO, V, etc., which are secondary hardening elements similar to cr, is increased, the amount of carbides will increase, so it is not preferable to contain a large amount. Based on the above findings, the present inventors were able to obtain a steel of the present invention that has high strength, excellent stickiness resistance, and high fatigue properties.

Next, the reason for limiting the composition range of the material of the present invention will be described.

C: Q, 25 ~ (L40X C forms a carbide with Cr, V, etc., and partially dissolves in the matrix to strengthen the base, so it is necessary to contain KO, 25X or more. If contained in large amounts, the toughness deteriorates, so the upper limit is usually set at 0.
-60X or less, but the present invention material needs to be 0.40X or less in order to improve thread fatigue characteristics.

Si: 1.50X or less Although Sl is necessary as a deoxidizing element during melting and refining, it also increases tempering softening resistance and raises the transformation point, so it also contributes to preventing coarsening of crystal grains during high-temperature quenching. Therefore, it is better to actively include it, preferably 0.2
Must be 0X or higher. However, since excessive content deteriorates hot workability and machinability, the upper limit was limited to 1.50% or less.

Km: 1.50X or less Mll is necessary as a deoxidizing and desulfurizing element during melting and refining, or is an effective element for improving hardenability, so it is better to actively include it. , preferably (1,
It should be 20X or more.

However, if it is contained excessively, weldability will deteriorate.
．． It was limited to 50% or less.

Cr: 3.10-6. OoX Cr must be contained in an amount of 3 LIOX or more in order to improve hardenability and increase resistance to temper softening. However, if excessively contained, the annealing properties after welding will deteriorate, so the content should be less than 7 to ox.

Mo: 0.30 to 1-50% Mo is an element that forms carbides and greatly contributes to increasing the tempering hardness due to secondary hardening, and must be contained in an amount of 0.30% or more. Moreover, 0.30% or more is required to improve the fatigue strength of screws. However, Mo
is expensive, and if it exceeds 1.50%, no improvement in the 4 fatigue properties can be expected, so it is set to 1.50X or less.

V: More than 0.4G (L8G%L-/, lower ■ forms carbides and suppresses crystal grain coarsening. 9, greatly contributes to secondary hardening during tempering, so Q, more than 4 ON and contain it.

However, if it is contained in excess, hot workability and grindability will deteriorate, and thread fatigue strength and toughness will also decrease.
, go must be as follows.

Nb, Ti: Q, 02-0.20% Nb, T1
(K is an element that does not easily form a solid solution at temperatures below 1000°C and is effective in preventing coarsening of crystal grains), and to obtain this effect, K
It is necessary to contain 0.02% or more. However, even if it is contained in excess, the above effect will not improve much, so 0.20
Must be less than or equal to X.

N1: 0.1~1.5X By adding Ni), the toughness after heat treatment is improved.

In addition, the fatigue life (screw) is stable, so 0. Contain IX or more. However, if excessively contained, the annealing characteristics after welding will deteriorate, so the content is limited to 1.5X or less.

Next, the characteristics of the material of the present invention will be explained in detail with reference to examples.

Examples Table 1: Chemical composition of test materials (X) The materials of the present invention and comparative materials having the compositions shown in Table 1 were melted, subjected to hot compression, and then subjected to cold air compression. Coil strip steel of OX15GM was manufactured and used as a sample material for various property tests.

Tempering Softening Characteristics Each specimen was heat treated under the same conditions as high-speed tool steel (quenching 1
200℃×2-oil cooling, tempering 550℃ 575, 600
The results of measuring the tempering hardness are shown in Table 2.

It can be seen that the material of the present invention satisfies the hardness of 87,500 or higher, which is necessary for the main body material.

Table 2: Temperature hardening Hv) Mechanical properties of the inventive material and comparison material
CX2-oil cooling, tempering 575℃X I Hr oil cooling 3
(repeated several times), a tensile test was conducted and the results are shown in Table 3.

Table 3 Mechanical properties (Note) Tensile test piece: JIS No. 13 B Comparative material 13.15.16 has the required hardness H as a body material
Although it satisfies the requirements (more than 100 mm SOO), the elongation is rather small and it is insufficient as a body material.

On the other hand, the materials of the present invention (11 to 9) have high hardness and tensile strength, and also have significantly high elongation.

A double-oscillator Schenck fatigue test was conducted on each sample material with torsion fatigue properties A1-16, and the results are shown in Table 4. In addition, the test material was 1220uX2-oil cooled and then heated for 3 hours at each temperature shown in Table 4.
Tempering was performed twice.

The material of the present invention exhibits better fatigue properties than any of the comparative materials, and is made by containing appropriate amounts of C, St, Mo, V, etc. (or by adding Nb and TI to these materials). It can be seen that lowering K Ct to about 0.25 to 0.40X and increasing Cr are effective in improving thread fatigue properties.

Table 4 Screws] Fatigue test results (screw) of the broken fabric when stress is applied Evaluated by number of repetitions.

(Note 2) The test piece dimensions are 1-0mm thick and 90am long.
(Gripping part 30-X2) 34M in e (parallel part 15
m), R5 of the grip part - As described above, the present invention has discovered a material suitable for the metal pantone body material, and its characteristics include high torsional fatigue properties, which are particularly important in practical use; It is also a material with excellent wear resistance), and can be made round to cope with the tendency for work materials to become more difficult to cut and for cutting to be more efficient.

Applicant: Daido Steel Co., Ltd. Agent Yoshio Kawaguchi

Claims (4)

[Claims] (1) CO, 25~0.40X, S l 1.5
0X or less, Mn 1.50X or less, Cr 110~a
, OOX, Me 0.30-1.50%, Vo, 4
Body material for metal band saws, containing 80% of Q over 0, with the remainder being F and unavoidable impurities. (2) C(L25~Q, 40X, 8 i 1.5
0X or less, Mml, 50% or less, Cr5L10~t
, 00%, Mn0.30-1.50%, Vo, over 40~cL80X and Nb Q, 02-0.20%, T
i A body material of a metal band containing one or two of O, 02 to 020X, with the remainder being F and unavoidable impurities. (3) CO, 25~Q, 40X, El s 1-
50X or less, MgI2.50X or less, NI G, 1
~15%, Cr 3.10~NOOX, Me 0.
A metal pantone body material containing 30 to 150% Vo, 40~o, and soX, with the remainder consisting of Fψ and inevitable impurities. (4) CG, 25~Q, 40X, S l 1.5
0X or less, Misl, 50% or less, N I G, 1
~1.5X, Cr! Ll O~! , 00%, M4
10.3 (1~1.50X, Vo, over 40~Q
, 80X and Nb Q, 02~0-20%, TIQ, 02
~ A metal bar/tonneau body material containing one to two types of L20X, with the remainder consisting of F and inevitable impurities.