[go: up one dir, main page]

CA2159358C - Wear-resisting high-manganese cast steel - Google Patents

Wear-resisting high-manganese cast steel

Info

Publication number
CA2159358C
CA2159358C CA002159358A CA2159358A CA2159358C CA 2159358 C CA2159358 C CA 2159358C CA 002159358 A CA002159358 A CA 002159358A CA 2159358 A CA2159358 A CA 2159358A CA 2159358 C CA2159358 C CA 2159358C
Authority
CA
Canada
Prior art keywords
cast steel
amount
weight
steel
resistance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA002159358A
Other languages
French (fr)
Other versions
CA2159358A1 (en
Inventor
Saburo Kunioka
Hiroshi Toriyama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shinhokoku Steel Corp
Original Assignee
Shinhokoku Steel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shinhokoku Steel Corp filed Critical Shinhokoku Steel Corp
Priority claimed from PCT/JP1994/000130 external-priority patent/WO1995020686A1/en
Publication of CA2159358A1 publication Critical patent/CA2159358A1/en
Application granted granted Critical
Publication of CA2159358C publication Critical patent/CA2159358C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Cutting Tools, Boring Holders, And Turrets (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)

Abstract

A high-manganese cast steel having excellent wear and impact resistances and comprising 1.3-1.4 % (by weight, the same will apply hereinbelow) of carbon, 0.05-0.20 % of silicon, 14.0-15.0 % of manganese, 0.5-1.5 % of chromium, 0.3-0.8 % of vanadium, 0.2-0.4 % of titanium, 0.5-1.0 % of molybdenum, and the balance consisting of iron and inevitable impurities.

Description

21593~8 TRANSLATION
D E S C R I P ~ I O N
"ABRASIVE RESISTANT HIGH MANGANESE CAST STEEL"
[Technical Field]
The present invention relates to an abrasive resistant high manganese cast steel used for a knife of an ore-crusher, or shockresistant and wearresistant parts such as a caterpillar shoe for a conveying device, and the like.
[Background Art]
A construction machine used for crushing various type of ores of mines, includes various types of parts such as a knife of a crusher, a caterpillar shoe for a conveying machine, a bucket knife, a rail and a rail point. The material for these parts is required to have not only a sufficient strength level as a structural member, but also an excellent abrasive resistance, a shock resistance and a corrosion resistance.
A high manganese cast steel, for example, Hadfield steel (carbon: 1-1.3 weight%, manganese: 11.5-13 wt~) has properties such as exhibiting an austenitic structure at room temperature, a low yield point, a high ultimate tensile strength, and a significant work hardening. Therefore, the hardness and the wear resistance of the steel can be increased by a cold working or surface abrasion. In general, a Hadfield steel is heated to 1050~ or higher, and then quickly cooled, to make an abrasive resistant and shockresistant tough steel, a surface portion of which has a high hardness and an inside portion of which has a high toughness.
Jap. Pat. Appln. KOKAI Publications. Nos. 54-43818, 57-39158 and 55-53513, disclose an abrasive resistant high manganese cast steel in which crystal grains are refined by adding a small amount of each of the elements for preparing a carbide, such as Ti, V, Cu, Zr, Ce, Mo, W and Nb, and another abrasive resistant high manganese cast steel in which a small amount of spherical carbide is precipitated on the base material of a high carbon-manganese steel.
However, in the former abrasive resistant high manganese cast steel, it is difficult to remarkably improve the abrasive resistance only by fining the crystal grains, and the degree of the improvement is limited.
In the latter abrasive resistant high manganese cast steel, the wear resistance can be improved to a certain degree by enhancing the precipitation of the spherical carbide. However, the austenite matrix itself is not improved but maintained as it is, and therefore it is difficult to obtain a sufficient abrasive resistance while maintaining a re~uired level in shock resistance.

2lss3s8 The present invention has been proposed to solve the above-described problems and the object thereof is to provide an abrasive resistant high manganese cast steel having an excellent abrasive resistance and an excellent shock resistance.
[Disclosure of Invention]
According to the present invention, there is provided an abrasive resistant high manganese cast steel characterized by containing: 1.3-1.4 weight% of C, O.05-0.20 weight% of Si, 14.0-15.0 weight% of Mn, 0.5-1.5 weight% of Cr, 0.3-0.8 weight% of V, 0.2-0.4 weight% of Ti, and 0.5-1.0 weight% of Mo, and a balance of Fe and inevitable impurities.
The reasons for specifying the ranges of the contents of the component elements will now be described one by one.
Regarding C, the content is determined in consideration of the balance between the carbide generating element amount and the Mn content. When the carbon content becomes lower than 1.3~, the carbide is not precipitated in an amount sufficient to reinforce the matrix, resulting in an insufficient wear resistance. In contrast, when the carbon content exceeds 1.4%, the carbide is generated by precipitation in an excessive amount, thus reducing the shock resistance. This is because the toughness of an alloy steel is generally improved as the content ratio of 2ls93~8 carbon with respect to that of Mn (Mn/C ratio) is increased.
Usually, Si is added to a high carbon and high manganese steel in an amount of 0.2-1.0 weight%.
The purposes of the addition of Si are to refine the bath and improve the bath flow when casting.
These purposes can be also achieved by using other means to refine the bath, which results in minimizing the amount of non-metal inclusions, and therefore an excessive addition of Si, which basically embrittles the austenite matrix, is not preferable. For this reason, the upper limit of the Si amount is set to 0.2%, in order to achieve the improvement of toughness as much as possible. The reason for setting the lower limit of the Si amount to 0.05%, is that Si enters inevitably from a scrap and can contribute to the refining effect as a deoxidizer even for a small degree. However, the function of Si as a deoxidizer can be achieved also by Al, and therefore the Si amount should preferably be as low as possible, to prevent an excessive deoxidization. The Si content should most preferably be in a range of 0.08 to 0.15%.
Mn is a main element for stabilizing the austenite matrix, and it is necessary to add it to make the Mn/C
ratio e~ual to or higher than a predetermined value, for the purpose of improving the toughness.
The necessary amount of Mn is determined in accordance 21S93~

with the carbon content. In order to achieve a good toughness, an Mn amount of 14% is necessary with respect to a carbon amount of 1.3%, and an Mn amount of 15% is necessary with respect to a carbon amount of 1.4%.
Cr serves to enhance the hardenability and improve the proof stress and abrasive resistance; however it decreases the toughness. The reason for setting the lower limit of the Cr amount to 0.5% is that a practical abrasive resistance cannot be obtained if the Cr amount lowers this limit. In contrast, the reason for setting the upper limit of the Cr amount at 1.5~, is that a practical shock resistance cannot be obtained of the Cr amount exceeds this limit.
V is a strong carbide generating element. With a small amount of addition of this element, the proof stress is improved, and the crystal grains are fined;
therefore, this element contributes to the improvement of the abrasive resistance. With an excessive amount of addition of this element, however, the toughness is decreased. In order to balance between the abrasive resistance and the shock resistance, the lower limit of the V amount is set to 0.3%, and the upper limit is set to 0.8%.
In similar to Ti, V is a strong carbide generating element. With a small amount of addition of this element, the crystal grains are fined; therefore, this 21~93~

element contributes to the improvement of the abrasive resistance. With an excessive amount of addition of this element, however, the toughness is decreased.
In order to balance between the abrasive resistance and the shock resistance, the lower limit of the V amount is set to 0.2%, and the upper limit is set to 0.4%.
Mo, with a small amount of addition, improves its yield point and raises the hardenability and the drawing resistance, without decreasing the toughness.
The abrasive resistance is improved as the carbide is generated. Thus, Mo is an effective element for preventing the occurrence of a crack in a thick cast product. In order to have such an effect exhibited, it is necessary to increase the Mo amount to 0.5% or more.
However, the effect of the addition of Mo is saturated at an amount of 1.0%, and therefore the upper limit is set to 1.0%.
~Brief Description of the Drawings]
FIG. 1 is a photograph showing a metal structurè
(magnification: 200 times) of an abrasive resistance high manganese cast steel according to an embodiment of the present invention;
FIG. 2 is a photograph showing a metal structure (magnification: 200 times) of a conventional cast steel; and FIG. 3 is a photograph showing a metal structure (magnification: 200 times) of another conventional cast steel.
[Best Mode to Carry out the Invention]
An embodiment of the present invention will now be described with reference to drawings and tables.
Table 1 shows an example of the composition for each one of Example 1 and Comparative Examples 1-4.
As shown in Table 1, Comparative Example 2 does not contain molybdenum, and Comparative Example 4 does not contain vanadium.
Table 2 shows the results of the examination with regard to various mechanical characteristics, carried out for each one of the cast steels of Example 1 and Comparative Examples 1-4. The items of the mechanical characteristics ex~mined are the ultimate tensile strength, the elongation, the reduction of area, the hardness and the value of impact energy. The hardness is expressed in a value of Brinell hardness. The value of impact energy was obtained by a 2mmV-notch Charpy test.

Table 1 Steel C Si Mn Cr V Ti Mo P S
type Example 1 A 1.33 0.09 14.5 1.45 0.66 0.21 0.67 0.020 0.003 Comparative B 1.35 0.67 14.8 1.40 0.66 0.23 0.67 0.019 0.003 Example 1 Comparative C 1.36 0.52 14.76 1.78 0.66 0.17 - 0.021 0.002 Example 2 Comparative D 1.34 0.43 18.73 0.42 0.05 0.03 0.18 0.027 0.001 Example 3 0 Comparative E 1.61 0.66 19.73 2.25 - 0.09 1.14 0.02 0.001Example 4 Co ~r~

Table 2 Value of Tensil Reduction impact Steel strenqth Elongation of area Hardness energy type N/mm2 (%) (%~ (HB) (kgf-m/cm2) Example 1 A 703.617.6 29.0 248 6.67 Comparative B 744.818.1 27.8 295 5.12 Example 1 Comparative C 639.9 8.1 11.3 258 2.44 Example 2 Comparative D 585 10.7 19.9 204 2.68 Example 3 Comparative E 636 6.5 5.1 282 2.47 Example 4 oo 21593~8 As is clear from Table 2, the results of the Example 1 are superior than those of the Comparative Examples 1 - 4. In particular, the Example is superior in the hardness and the impact resistance of these characteristics.
FIG. 1 (photograph) is a 200-times-magnified metal structure of a sample taken from the cast steel of Example 1. As is observed in this figure, granular or angular-shaped carbides are precipitated in crystal grains. Apart from these carbides having relatively large sizes, it is also observed that fine carbides are precipitated on the austenite base in its entire surface. These fine carbides are a mixture of vanadium carbides, titanium carbides, molybdenum carbides and chromium carbides, which are very hard and contribute to the improvement of the abrasive resistance without losing the necessary toughness.
FIG. 2 (photograph 2) is a 200-times-magnified metal structure of a sample taken from the cast steel of Comparative Example 4. As can be observed, a small amount of spherical molybdenum carbides are dispersedly precipitated in crystal grains, yet the austenite matrix is as it has been.
FIG. 3 (photograph 3) is a 200-times-magnified metal structure of a sample taken from the cast steel of Comparative Example 3. As can be observed, a small amount of spherical molybdenum carbides are dispersedly precipitated in crystal grains, yet the austenite matrix is as it has been.
The cast steel of the Example and those of the Comparative Example (Steel type: GISSCMnH-ll of JIS
standard) were used for an upper mantle of an ore crusher, and the lives of these types of steel were compared. It was confirmed with the result of the comparison that the life of the former was 1.43 times longer than that of the latter.
[Industrial Applicability]
The cast steel of the present invention has a significantly improved abrasive resistance, as compared to the conventional steel. Therefore, the life of the various parts including the knife of an ore crusher, or the caterpillar shoe of a conveying machine can be remarkably prolonged.

Claims

C L A I M S
1. An abrasive resistant high manganese cast steel characterized by comprising: 1.3-1.4 weight% of C, 0.05-0.20 weight% of Si, 14.0-15.0 weight% of Mn, 0.5-1.5 weight% of Cr, 0.3-0.8 weight% of V, 0.2-0.4 weight% of Ti, and 0.5-1.0 weight% of Mo, and a balance of Fe and inevitable impurities.
CA002159358A 1994-01-31 1994-01-31 Wear-resisting high-manganese cast steel Expired - Fee Related CA2159358C (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP1994/000130 WO1995020686A1 (en) 1992-06-26 1994-01-31 Wear-resisting high-manganese cast steel

Publications (2)

Publication Number Publication Date
CA2159358A1 CA2159358A1 (en) 1995-08-03
CA2159358C true CA2159358C (en) 1999-09-14

Family

ID=14098154

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002159358A Expired - Fee Related CA2159358C (en) 1994-01-31 1994-01-31 Wear-resisting high-manganese cast steel

Country Status (2)

Country Link
AU (1) AU673050B2 (en)
CA (1) CA2159358C (en)

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI904500A7 (en) * 1990-09-12 1992-03-13 Lokomo Oy SLITSTARKET STAOL OCH FOERFARANDE FOER FRAMSTAELLNING AV DETTA.

Also Published As

Publication number Publication date
CA2159358A1 (en) 1995-08-03
AU673050B2 (en) 1996-10-24
AU5891894A (en) 1995-08-15

Similar Documents

Publication Publication Date Title
JP2003027181A (en) High toughness wear-resistant steel
KR102009630B1 (en) Grater
SE528454C2 (en) Extractable curable martensitic stainless steel including titanium sulfide
JP2005256169A (en) Abrasion resistant steel plate with excellent low temperature toughness and method for producing the same
US5601782A (en) Abrasive resistant high manganese cast steel
JP3360687B2 (en) High-strength, high-toughness wear-resistant steel
EP0692548B1 (en) Wear-resisting high-manganese cast steel
JP2001049387A (en) High toughness high temperature wear resistant steel
KR100415626B1 (en) High Strength Wear Resistance Steel with Excellent Hardenability
CA2159358C (en) Wear-resisting high-manganese cast steel
JPH07145444A (en) High strength spheroidal graphite case iron
JPH08144009A (en) High toughness wear-resistant cast steel
JPH0770700A (en) High proof stress and high corrosion resistant austenitic stainless cast steel
NZ290640A (en)
CA1267304A (en) Manganese steel
JP3005363B2 (en) Wear resistant high manganese cast steel
SU1749307A1 (en) Steel
RU2230817C1 (en) Cast iron
KR100198972B1 (en) Complex carbide
SU1049557A1 (en) Cast iron
JPH05239589A (en) High strength nonheat-treated steel
JP7239056B1 (en) Wear-resistant steel plate
KR101209483B1 (en) High strength cutting knife tool steel for steel cut
KR100256366B1 (en) The hyper eutectic high chrome composit carbide line alloy for excellent wear resistance and impact toughness
JP3157298B2 (en) High strength, high toughness Cr heat resistant steel

Legal Events

Date Code Title Description
EEER Examination request
MKLA Lapsed