KR20010113710A - Method for producing a wear-resistant surface on components consisting of steel and machine with at least one component of this type - Google Patents

Abstract

According to the invention, components consisting of steel are provided with a protective coat (6) with an intermediate layer which is harder than steel and a still harder outer layer by successively melting superposed layers (8, 9) consisting of aluminium-bronze onto the steel base material (7).

Description

METHOD FOR PRODUCING A WEAR-RESISTANT SURFACE ON COMPONENTS CONSISTING OF STEEL AND MACHINE WITH AT LEAST ONE COMPONENT OF THIS TYPE}

It is well known to harden the surface of parts made of steel to form a hard surface. However, the heat treatment required for the curing treatment is expensive and requires much experience. In addition, the hardness obtained from several hardening treatments is not sufficient. Hardening of the surface also has the disadvantage that the hardness is generally small and the risk of flaking is high. Therefore, the tool life is generally short.

The present invention relates to a method for producing a surface of a wear resistant steel part and to an apparatus comprising at least one steel part having a surface which is at least partially resistant to wear.

1 is a partial head cross section of a two-stroke diesel engine;

2 an enlarged view of the cross section of the device according to FIG. 1 with a protective sheath;

The object of the present invention is to start from these problems and improve the method and apparatus of the kind mentioned above in a simple and inexpensive way, which not only increases the hardness and thickness of the area resistant to wear, but also makes the support reliable. It is also to simplify manufacturing.

The object of the present invention is to provide a steel base material to form a harder intermediate layer and a much harder outer layer compared to steel in connection with the method according to the concepts above in the claims, It is achieved by dissolving a plurality of overlapping layers of aluminum-bronze alloys. It is also an object of the present invention to provide a plurality of, mainly two, overlapping aluminum-bronze alloys in which a protective coat, which is provided for forming a wear resistant surface in connection with the device according to the above concept, is dissolved in a steel base material. Achieved by layering.

Aluminum-bronze alloys, which primarily dissolve through welding, surprisingly prove that the outer layer is harder than the inner layer. In the experiments on the two layers welded in turn, the hardness of the inner layer was 300HV to 400HV and the hardness of the outer layer was 500HV to 600HV, which was much larger than the inner layer. Thus, in a base material consisting of steel and having a hardness of 100 HV to 200 HV, an intermediate layer is preferably automatically formed which is relatively hard outer layer and softer than the outer layer but much harder than steel. This ensures that the hardness between the base material and the outer layer resistant to wear is balanced in several steps, not just one. As a result, the parallel shearing force acting on the surface and the drag force perpendicular to the surface are reliably transmitted to the base material. This preferably ensures high stability of flaking. As a result, the lifetime guaranteed by the high hardness of the outer layer can be extremely effective. The measures according to the invention thus preferably ensure high economics.

Preferred forms and variations of the foregoing measures suitable for the purpose of the invention are set forth in the claims. It is proved to be particularly suitable for the purpose of the present invention to preheat the respective receiving materials first in the furnace before dissolving the layer made of aluminum-bronze alloy. By preheating, the hardness value of the inner layer to the outer layer can be raised. Thus, the desired hardness can be simply adjusted to suit the individual situation.

The preheating temperature was found to be particularly preferred at 350 ° C. This allows a maximum hardness value to be obtained without changing the structure of the base material.

Another possibility of adapting the desired hardness value to the individual situation is a change in the aluminum-bronze alloy synthesis that is preferably available. Particularly, for greater hardness, aluminum-bronze alloys containing 13% to 16% aluminum, 4% to 5% iron, 0.2% to 0.8% silicon, 1% to 2% manganese, 0.2% carbon or less and residual copper are used. It is appropriate. The use of an aluminum-bronze alloy comprising 8% to 11% aluminum, 4% to 5% nickel, 3% to 5% iron, 1% to 2% manganese and residual copper can result in relatively low hardness. In this way the hardness of the outer and / or inner layers can be tailored to the individual needs.

In most cases, it is preferred that the entire layer forming the protective coating consists of the same aluminum-bronze alloy. This makes it easier to manufacture and results in particularly homogeneous bonding between successive layers.

In another preferred form, in order to improve the input quality, the coating may be coated with MoS2 or the like which is liable to wear on an outer layer made of aluminum-bronze alloy. Because of this input layer, which disappears by itself during the inflow phase, the rigid support layer formed by the outer layer of aluminum-bronze alloy is exposed and effective only after some inflow time. This has a desirable effect on life extension.

Other preferred embodiments and suitable variations of the foregoing solutions are set forth in the remaining dependent claims and are explained in more detail with reference to the drawings in the following examples.

The present invention can be applied wherever the protective coating on the surface of the steel component requires a hardness of more than 100HV to 200HV. This is suitable for the case of different engine parts with high load bearing faces, for example piston rings, cross head guides. By using a hard protective coating compared to the base material, the wear rate can be reduced and the service life can be extended. Therefore, the hardness of the surface under load is as large as possible and the bonding with the base material is as good as possible.

The frame cross section of the two-stroke diesel engine of FIG. 1 includes a standing wall 2 on both sides of the cross head 1. At the end of the side guide block 3 in the cross head 1 is provided a guide plate 4 with bearing surfaces facing each other. The guide plate has bearing surfaces facing each other and moves on a guide rail 5 provided on the stand side.

The guide plate 4 and the guide rail 5 are made of standard steel as a base material, and are provided in the bearing surface area | region which mutually faces the protective sheath 6 which is larger in hardness and has a longer life. Such protective sheaths can of course also be applied to other steel parts under similar load, for example bearing bushes or piston rings.

The protective sheath 6 is made of an aluminum-bronze alloy and, as can be seen in FIG. 2, two layers 8, which are in turn melted and overlapped with each other by welding to the steel base material 7 in accordance with the object of the invention. 9) is manufactured. The hardness of the steel is generally from 100 HV to 200 HV. The hardness size of the aluminum-bronze alloy is generally 200 HV. The inner layer 8 which is first welded to the base material 7 made of steel surprisingly already has a hardness of about 300 HV to 400 HV. The hardness of the second layer, the outer layer 9, is surprisingly much higher, from about 500 HV to 600 HV. The outer layer 9 is therefore particularly suitable as a wear resistant support layer which ensures a long life even when driving is difficult.

If a very solid support layer is in effect after first going through a certain inflow step, this is highly desirable. In this case, the inlet layer 10 coated on the outer layer 9 is made of a relatively brittle material, for example MoS ₂ , and disappears spontaneously during the inflow step, which is then made of an aluminum-bronze alloy and the hardness of A large outer layer 9 is shown for supporting as shown in the right side of FIG. 2.

The relatively low hardness inner layer 8 is actually used as a bonding layer of moderate hardness that connects between the very hard outer layer 9 and the base material 7 which is relatively soft compared to the outer layer. This ensures that the hardness between the outer layer 9 and the base material 7 is balanced in stages. At the same time, the inner layer 8 has a relatively small hardness, resulting in high viscosity and impact strength. As a result, the shear force parallel to the surface and the drag force (shown by arrows 11 and 12) perpendicular to the surface can be absorbed well and transferred to the base material 7. In the example shown, the layers 8, 9 to be welded in turn are of the same thickness. The thickness of the two layers 8, 9 can of course be different or different. Although the embodiment with two layers 8, 9 welded in turn in the example shown is particularly preferred, welding two or more layers in turn is likewise conceivable.

When producing the two layers 8 and 9, 8% to 25% of aluminum, 0.2% to 10% of each of styrene (Sb), cobalt (Co), beryllium (Be), chromium (Cr) and tin (Sn) ), At least one of manganese (Mn), silicon (Si), cadmium (Cd), zinc (Zn), iron (Fe), nickel (Ni), lead (Pb) and carbon (C) and residual copper Preference is given to using aluminum-bronze alloys. If the inner and / or outer layers 8, 9 are to have particularly high hardness values, aluminum 13% to 16%, iron 4% to 5%, silicon 0.2% to 0.8%, manganese 1% to 2%, carbon 0.2 Preference is given to using aluminum-bronze alloys comprising up to% and residual copper. If the hardness of the inner and / or outer layers 8, 9 is slightly small, it comprises 8% to 11% aluminum, 4% to 6% nickel, 3% to 5% iron, 1% to 2% manganese and residual copper. An aluminum-bronze alloy can be used. Depending on the size of the hardness, an aluminum-bronze alloy having a large or small hardness value may be used for the inner or outer layers 8 and 9. However, it is generally desirable to use the same aluminum-bronze alloy in both layers 8, 9.

As mentioned above, the two layers 8, 9 can be coated by a welding process. In this case, an electric arc or laser beam or flame may be used.

To increase the hardness as desired, the receiving parts can be preheated before each aluminum layer is deposited. That is, the base material can be preheated before the inner layer 8 is welded, and the coated intermediate product can be preheated before the outer layer 9 is welded. Preheating is preferably done in the furnace. It was found that the preheating temperature at this time is about 350 ° C. being particularly preferred.

Claims (12)

As a method for manufacturing a surface of abrasion resistant steel parts, In order to form a protective sheath 6 comprising a harder intermediate layer and a much harder outer layer than steel, a plurality of layers 8, 9 made of aluminum-bronze alloy and overlapping each other are applied to the base material 7 made of steel. How to dissolve. In claim 1, Method for dissolving two layers (8, 9) made of aluminum-bronze alloy. The method of claim 1 or 2, Forming a layer (8, 9) of the protective sheath (6) by welding. The method according to any one of claims 1 to 3, A method of preheating the material covered in each layer in a furnace before depositing each layer (8, 9) of said protective coating (6). In claim 4, Said preheating at about 350 ° C. The method according to any one of claims 1 to 5, Forming a layer (8, 9) of the protective coating (6) from the same alloy. In any one of claims 1 to 6, The layers 8 and 9 of the aluminum-bronze alloy forming the protective sheath 6 are made from 8% to 25% of aluminum, 0.2% to 10% of styrene, cobalt, beryllium, chromium, tin, manganese and silicon, respectively. At least one of cadmium, zinc, iron, nickel, lead, carbon, and residual copper. In claim 7, At least one layer (8, 9) of the protective coating (6) made of an aluminum-bronze alloy comprises 13% to 16% aluminum, 4% to 5% iron, 0.2% to 0.8% silicon, 1% to 2% manganese, A method consisting of up to 0.2% carbon and residual copper. In claim 6 or 7, At least one layer (8, 9) of the protective coating (6) made of an aluminum-bronze alloy comprises: 8% to 11% aluminum, 4% to 6% nickel, 3% to 5% iron, 1% to 2% manganese, and Method consisting of residual copper. An apparatus comprising at least one steel component having a surface that is at least partially resistant to wear, the apparatus comprising: A plurality of, mainly two aluminum-bronze alloys, provided with the protective sheath 6 to form a wear-resistant surface, which is superposed and dissolved on a base material 7 made of steel. Device consisting of layers (8, 9). In claim 10, The hardness of the inner layer (8) close to the base material of the protective coating is 300 HV to 400 HV, and the hardness of the outer layer (9) on the surface side is 500 HV to 600 HV. The method of claim 10 or 11, The outer layer (9) made of aluminum-bronze alloy is recoated with the inlet layer (10) made of a material which is subject to wear.