JPS6133054B2 - - Google Patents

Description

[Detailed description of the invention]

This invention has high strength, excellent wear resistance, and self-lubricating properties, and is particularly suitable for use in manufacturing automobile door fittings, gears, cams, slide guide members, etc. that require these characteristics. The present invention relates to suitable iron-based sintered alloys. Conventionally, iron-based sintered alloys containing low-melting point metals, sulfur compounds, etc. dispersed therein, hardened steel, case-hardened steel, and the like have been used to manufacture this type of member. However, although iron-based sintered alloys have good self-lubricating properties due to the low melting point metals and sulfur compounds dispersed in the matrix, these lubricating components inhibit the sinterability of the matrix during sintering. It is difficult to obtain high-strength steel, and hardened steel and case hardened steel have high surface hardness, making them excellent in wear resistance, but they have poor self-lubricating properties, so they do not mate with other parts. Compatibility deteriorates and problems such as seizure often occur, and at present, a material that combines strength, wear resistance, and self-lubricating properties has not yet been obtained. Therefore, from the above-mentioned viewpoint, the present inventors conducted research focusing on iron-based sintered alloys in order to obtain materials with the above-mentioned characteristics. : Less than 0.1-0.8%, Cu: 0.5-10
%, Ni: 0.5~20%, Mo: 0.1~5%, S: 0.6~
2%, P: 0.05 to 2%, further contains Sn: 0.05 to 3% as necessary, and the remainder is Fe and unavoidable impurities. ), the resulting iron-based sintered alloy has a structure in which metal sulfides mainly consisting of iron sulfide and sulfide steel are uniformly dispersed in a high-strength and high-hardness matrix. The sulfide provides good self-lubricating properties, and it also has good compatibility with the mating part and does not damage the mating part, and the base material provides high strength and excellent wear resistance. They obtained the knowledge that they would be able to secure the following. This invention was made based on the above knowledge, and the reason why the component composition range was limited as described above will be explained below. (a) C In addition to forming a solid solution in the base material, the C component has the effect of forming a martensitic phase to improve the strength and wear resistance of the alloy, but its content is 0.1
If it is less than %, the desired effect cannot be obtained,
On the other hand, if the content exceeds 0.8%, a relatively large amount of free graphite will be dispersed and precipitated in the matrix, resulting in a heterogeneous material.
Its content was set at 0.1% to less than 0.8%. (b) Cu The Cu component forms a solid solution in the substrate together with C, Ni, and Mo components to improve its wear resistance, and also combines with S to form a sulfur compound to improve self-lubricating properties. However, if the content is less than 0.5%, the desired effect of improving wear resistance and self-lubricating property cannot be obtained, while if the content exceeds 10%, the amount of metallic Cu remaining dispersed in the substrate will not be obtained. Since the wear resistance of the alloy deteriorates as the amount increases, the content was set at 0.5 to 10%. (c) Ni The Ni component has the effect of forming a solid solution in the base material, strengthening it, and improving the strength and wear resistance of the gold, but if its content is less than 0.5%, the desired strength cannot be achieved. On the other hand, if the content exceeds 20%, the base material becomes soft and the abrasion resistance deteriorates, so the content was set at 0.5 to 20%. (d) Mo The Mo component forms a solid solution in the base material, strengthens it, and becomes additively strengthened especially when coexisting with Cu and Ni, thereby increasing the strength and wear resistance of the alloy. However, if the content is less than 0.1, the desired effect cannot be obtained in the above action, while if the content exceeds 5%, not only will the alloy strength decrease, but it will also be economical. Since there is no
%. (e) SS The S component mainly reacts with Fe and Cu components to form metal sulfides, which gives the alloy self-lubricating properties and has the effect of significantly mitigating the aggressiveness of mating parts. The content is
If the content is less than 0.6%, the formation of metal sulfides is too small and the desired effect cannot be obtained. On the other hand, if the content exceeds 2%, the amount of metal sulfides formed is too large, leading to a decrease in strength. Therefore, the content was set at 0.6 to 2%. (f) P The P component generates a liquid phase during sintering (so-called liquid phase sintering action), activates sintering, and solidifies the C, Ni, Cu, and Mo components into the matrix. It promotes dissolution diffusion, forms a martensitic phase, etc., and also brings about precipitation of P eutectic, thereby increasing the density (strengthening) of the alloy and improving wear resistance. If the content is less than 0.05%, the desired effect cannot be obtained, while if the content exceeds 2%, the alloy will become brittle, so the content was set at 0.05 to 2%. (g) Sn The Sn component has the effect of forming a solid solution in the matrix and further improving the strength and hardness of the alloy.
It is included as necessary when these properties are particularly required, but if the content is less than 0.05%, the desired effect of improving the above properties cannot be obtained, whereas if it is included in excess of 3%, Since the base material becomes too hard and the self-lubricating properties deteriorate, the content was set at 0.03 to 3%. Next, the iron-based sintered alloy of the present invention will be explained using examples and comparing with comparative examples. Example Raw material powders include iron powder with a particle size of -100mesh, S powder with a particle size of -350mesh, Cu-P alloy powder (containing 8% P) with a particle size of -325mesh, Cu powder with a particle size of -325μm, and carbonyl Ni powder with a particle size of -3μm. Powder, 325mesh
Ni-P alloy powder (P: 12% content),
100mesh natural graphite powder, 3μm Mo powder,
-200mesh Sn powder was prepared, these raw powders were blended into the composition shown in Table 1, mixed for 30 minutes in a V-type mixer, and molded into a green compact at a pressure of 5ton/ ^cm2 . Then, by sintering in an endothermic gas atmosphere at a temperature of 1050 to 1150°C for 0.5 hours, the sintered alloys 1 to 1 of the present invention having a final component composition that is substantially the same as the blended composition are obtained. No. 15 and Comparative Sintered Alloys 1 to 11 were manufactured, respectively. In addition, Comparative Sintered Alloys 1 to 11 all have compositions in which the content of any of the constituent components (indicated with an asterisk in Table 1) is outside the scope of this invention. It is something.

【table】

[Table] Next, the resulting sintered alloys of the present invention 1~
15 and Comparative Sintered Alloys 1 to 11, the transverse rupture strength and Vickers hardness were measured, and test piece dimensions: 25 mm x length 6 mm, mating material: JIS/SCM-8
(hardness: HRC 35), test surface pressure: 5Kg/cm ² , friction speed: 6.8m/sec, test time: 5 minutes, lubricant: No use (dry), surface contact sliding friction type. A wear test was conducted, and the average wear depth of the test piece and the mating material (all average of three pieces) was measured. These measurement results are also shown in Table 1. From the results shown in Table 1, the present invention sintered alloy 1
Comparative sintered alloys 1 to 15 all have high strength and hardness, excellent wear resistance, and very little wear on the mating material, whereas comparative sintered alloys 1 to 11 It is clear that the properties of at least one of strength, wear resistance, and self-lubricity are inferior. As mentioned above, the iron-based sintered alloy of the present invention has high strength as well as excellent wear resistance and self-lubricating properties, so it can be used in automobile door fittings, gears, cams, etc. that require these properties. When used in the production of slide guide members and the like, these members have industrially useful properties such as stably exhibiting excellent performance over an extremely long period of time.

Claims (1)

[Claims] 1 C: 0.1 to less than 0.8%, Cu: 0.5 to 10%, Ni: 0.5 to 20%, Mo: 0.1 to 5%, S: 0.6 to 2%, P: 0.05 to 2%, , with the remainder consisting of Fe and unavoidable impurities (at least % by weight), and a structure in which metal sulfides mainly consisting of iron sulfide and copper sulfide are uniformly dispersed in the matrix. A high-strength iron-based sintered alloy with excellent wear resistance and self-lubricating properties. 2 Contains C: 0.1 to less than 0.8%, Cu: 0.5 to 10%, Ni: 0.5 to 20%, Mo: 0.1 to 5%, S: 0.6 to 2%, P: 0.05 to 2%, and further, Sn: 0.05 to 3%, with the remainder consisting of Fe and unavoidable impurities (wt%), and a structure in which metal sulfides mainly consisting of iron sulfide and copper sulfide are uniformly dispersed in the matrix. A high-strength iron-based sintered alloy with excellent wear resistance and self-lubricating properties.