Steel powder composition and sintered body thereof

a technology of steel powder and composition, which is applied in the field of steel powder composition and a sintered body thereof, can solve the problems of poor sinterability, poor dimensional stability, non-uniform sintered density, etc., and achieves low sintered density, good sintering effect, and good dimensional control

US20120177531A1Inactive Publication Date: 2012-07-12TAIWAN POWDER TECH CO LTD
3 Cites 6 Cited by

Patent Information

Authority / Receiving Office
US · United States
Patent Type
Applications(United States)
Current Assignee / Owner
Publication Date
2012-07-12
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

A powder composition and a sintered body thereof are presented. The powder is a martensitic stainless steel powder for powder injection molding without deformation problems during sintering. The powder composition includes 0.80-1.40 weight percent (wt %) of carbon (C), less than 1.0 wt % of silicon (Si), less than 1.0 wt % of manganese (Mn), 15.0-18.0 wt % of chromium (Cr), 0.10-2.50 wt % of titanium (Ti), and the remainder iron (Fe). The powder can be sintered with a sintering temperature varying within 50° C. and can reach a high density without distortion, and thereby a good dimensional stability is obtained.
Need to check novelty before this filing date? Find Prior Art

Description

FIELD OF INVENTION

[0001] The present invention relates to a steel powder composition and a sintered body thereof, and more particularly to a martensitic stainless steel powder composition for metal injection molding, which has an improved dimensional control, and a sintered body thereof.BACKGROUND OF THE INVENTION

[0002] Metal injection molding (MIM) includes processes such as mixing a metal powder and a polymer binder, molding with an injection molding machine, debinding, and sintering at high temperatures, to obtain a metal part of near net shape. The technology involves in two fields, that is, powder metallurgy and plastic injection molding. Due to the high strength and hardness requirements for a MIM material, martensitic stainless steel is widely used, for example, steel species such as Japanese SUS410 series, Japanese SUS420 series, and Japanese SUS440C series.

[0003] However, the martensitic stainless steel powders generally have problems of poor sinterability, such as poor dimens...

Examples

embodiment 1

[0030]the alloy composition of this embodiment is shown in Table 1. In this embodiment, a titanium-containing pre-alloyed powder prepared by gas atomization is subjected to the process in Comparative Embodiment 1. FIG. 5 shows the sintering characteristics of this embodiment. The sintering window of Embodiment 1 is increased to 50° C., that is, within ±25° C. Such a sintering window improves the sinterability significantly, and is capable of being used in a common sintering furnace in the industry.

embodiment 2

[0031]the alloy composition of this embodiment is shown in Table 1. In this embodiment, titanium (Ti) is provided by adding 1.0 wt % of the titanium carbide (TiC) powder, and this powder mixture is subjected to the process in Comparative Embodiment 1. FIG. 6 shows the sintering characteristics. The sintering window of this embodiment is increased to 20° C., that is, within ±10° C.

embodiment 3

[0032]the alloy composition of this embodiment is shown in Table 1. In this embodiment, titanium (Ti) is provided by adding 2.0 wt % of the titanium carbide (TiC) powder, and this powder mixture is subjected to the process in Comparative Embodiment 1. FIG. 7 shows the sintering characteristics. The sintering window of this embodiment is increased to 40° C., that is, within ±20° C., indicating that the addition of titanium carbide (TiC) powder improves the sintering behavior.