JP2014534335A - White metal Babbit for rolling mill bush - Google Patents

Abstract

From about 5.0 wt% to 9.0 wt% antimony, from about 3.0 wt% to 8.0 wt% copper, from about 0.1 wt% to 0.7 wt% cobalt, and the balance tin An essentially tin-based white metal alloy.

Description

Cross-reference of related applications. S. C. Claims the benefit of US Provisional Application No. 61 / 541,395, filed September 30, 2011 under §119 (e), the entire contents and spirit of which are incorporated herein by reference. Has been.

Background 1. Field Embodiments and aspects of the present invention relate to tin-based white metal alloys useful in a variety of industrial applications, including rolling mill oil film bearing bushings.

2. Description of Related Art The most prominent white metal alloy used in oil film bearings in the field of rolling mills is described as ASTM B23 # 2 (referred to herein as ASTM # 2), and antimony and copper are used as alloying elements. And mainly made of tin. ASTM # 2 is well understood and is easily deposited on the bushing shell by centrifugal casting, spray deposition, or welding. Unfortunately, ASTM # 2 has a relatively low fatigue resistance, so the load capacity of bearings made from this material is limited.

  Various versions of nickel hardened white metal alloys are used, the usual version being called Tuftin. Although these alloys can be cast and welded, they contain nickel, which is an undesirable heavy metal for environmental reasons.

  US Pat. No. 6,589,372 B1 (Roeingh et al.) Discloses the use of a known tin-based white metal alloy consisting essentially of antimony, copper, zinc, silver, and tin. Roeingh alloys are suitable for centrifugal casting applications. However, due to the brittle nature of the zinc component, this alloy cannot be easily drawn into wires for use in spraying and welding applications.

  U.S. Pat. No. 4,140,835 (Goddard) and UK patent application 2146354A disclose cobalt as a component of a tin-based white metal alloy that also contains cadmium. Cadmium is a known carcinogen that is undesirable because it is banned from most workplaces.

  U.S. Pat. Nos. 4,150,983 (Mori) and 5,512,242 (Tanake et al.) Disclose alloys in which cobalt is utilized with chromium. The inclusion of chromium is not feasible because it does not dissolve easily under normal alloying conditions.

  U.S. Pat. No. 4,795,682 (Turner et al.) Discloses a tin / cobalt alloy useful as a sacrificial coating designed to adsorb particulates. Such coatings lack the toughness required for high load oil film bearing applications, and the disclosed use of cobalt at elevated percentage levels impedes the flow characteristics required for casting or welding processes.

SUMMARY Briefly, aspects of the present invention relate to tin-based white metal alloys that are universally useful for centrifugal casting, spraying, and welding applications.

  Aspects of the present invention also relate to a tin-based white metal alloy having increased strength and fatigue resistance required for use in high load oil film bearings of the type commonly found in the metal industry.

  Embodiments of the present invention further relate to a tin-based white metal alloy that is low in toxicity and generally free of carcinogenic components such as cadmium.

  In one embodiment, an aspect of the present invention provides a zinc component and a silver component of the alloy disclosed in US Pat. No. 6,589,372B1 above, between about 0.1 wt% and 0.7 wt%. A range of amounts may be achieved by substituting cobalt, in which case amounts in the range between 0.2% and 0.5% by weight are considered optimal.

DETAILED DESCRIPTION OF THE INVENTION In order to facilitate an understanding of the embodiments, principles and features of the present invention, they are described below with respect to implementation in an exemplary embodiment. In particular, they are described in the background that they are new and non-obvious tin-based white metal alloys.

  However, embodiments of the present invention are not limited to use in the described system.

  The components and materials described below in configuring the various embodiments are intended to be illustrative and not limiting. Many suitable components and materials that perform the same or similar functions as the materials described herein are intended to be included within the scope of embodiments of the present invention.

  The tin-based white metal alloy according to the present invention contains tin, antimony and copper as main components, to which cobalt is added. It has been found that the addition of cobalt in an amount greater than about 0.7% by weight detrimentally reduces the fluidity of the resulting alloy. Accordingly, it has been found that the addition of between about 0.1% and 0.7% by weight of cobalt is effective in achieving the above objective, with about 0.2% by weight Addition between ˜0.5% by weight is optimal.

  The tin-based white metal alloy of the present invention consists essentially of the components listed in the following examples:

Example I
Antimony 5.0-9.0 mass%
Copper 3.0-8.0 mass%
Cobalt 0.1-0.7 mass%
Tin balance

Example II
Antimony 6.0-8.0 mass%
Copper 3.0-8.0 mass%
Cobalt 0.1-0.7 mass%
Tin balance

Example III
Antimony 6.0-8.0 mass%
Copper 6.0-7.0 mass%
Cobalt 0.1-0.7 mass%
Tin balance

Example IV
Antimony 6.0-8.0 mass%
Copper 6.0-7.0 mass%
Cobalt 0.2-0.5 mass%
Tin balance

Example V
Antimony 6.0-8.0 mass%
Copper 6.0-7.0 mass%
Cobalt 0.2-0.5 mass%
Tin balance

  The resulting alloy of the present invention may be centrifugally cast and drawn into wire for use in spraying or welding applications. In addition, the alloys of the present invention have the strength and fatigue resistance required for use in high load bearing applications, such as steel manufacturing industry applications, and are also prohibited or otherwise harmful components. Not included.

The fatigue resistance of a white metal alloy can be determined experimentally through the use of tensile / compressed specimens that are repeated until failure. Table 1 shows laboratory test data comparing the alloys of the present invention with those commonly used in the art. According to the test data, the fatigue strength of the alloy containing 0.3% to 0.5% cobalt has excellent fatigue resistance superior to other alloys often used in rolling mill applications. The test data shown was measured according to ASTM E 466 with an applied load of 7,500 psi (51.7 MPa) and a test frequency of 10 Hz.

  While embodiments of the invention have been disclosed in an exemplary form, many changes, additions and deletions may be made from the spirit and scope of the invention and its equivalents as set forth in the following claims. It will be apparent to those skilled in the art that it can be made herein without departing.

Claims (10)

  About 5.0 wt% to 9.0 wt% antimony, about 3.0 wt% to about 8.0 wt% copper, about 0.1 wt% to about 0.7 wt% cobalt, and the balance A tin-based white metal alloy consisting essentially of tin.   The alloy of claim 1, wherein the content of antimony is about 6.0% to about 8.0% by weight.   The alloy of claim 1, wherein the copper content is about 6.0 wt% to about 7.0 wt%.   The alloy of claim 1, wherein the cobalt content is from about 0.2 wt% to about 0.5 wt%.   The alloy of claim 1 suitable for use in high load bearings for the steel manufacturing industry.   The alloy of claim 1 suitable for use in high load bearings used in power generation equipment.   The alloy of claim 1, suitable for use in sprayed and welded bearings.   2. An alloy according to claim 1 suitable for use with cast-formed barbite bearings.   About 6.0% to about 8.0% by weight antimony, about 6.0% to about 7.0% copper, about 0.2% to about 0.5% cobalt, and the balance A tin-based white metal alloy consisting essentially of tin.   The heavy load bearing for the steel manufacturing industry; suitable for use in at least one of heavy load bearings for use in power generation equipment; blown and welded bearings; or cast formed barbite bearings. alloy.