JPS6240347A - Austenitic hot tool steel - Google Patents

Abstract

PURPOSE:To manufacture an austenitic hot tool steel for a material for a copper extruding liner with an ordinary electric furnace at a low cost without using an expensive alloy element by using a high Mn-Cr-Ni steel contg. various austenitizing elements. CONSTITUTION:An austenitic alloy steel contg., by weight, 0.1-0.8% C, 0.1-1.5% Si, 8-30% Mn, 5-20% Cr, 1-15% Ni, 0.2-3.0% V, 0.1-2% Nb, 0.05-0.5% N and 0.1-3% Mo and/or 0.1-6% W (0.1<Mo+1/2W<=6%) is used as stock to manufacture a material for a copper extruding liner. The material for the copper extruding liner used at a high temp. is obtd. at a low cost without using an expensive starting material such as low-C Fe-Cr or metallic Cr or applying a special method such as vacuum decarburization with oxygen.

Description

[Detailed description of the invention] [Field of application of Kogyo T] Akira Motoyaku has developed a hot work Ju that exhibits 4-injection performance in a high temperature range as an alternative to heat-resistant steel A286, which has IJ conventions in manufacturing and is also expensive.
1. This relates to a liner material that is highly effective when used as a liner for extrusion.

[Conventional technology]

Conventionally, hot-worked A steels such as A-S-H19 have been used for copper extrusion and liner materials, but these have 600 to 700
It becomes the limit for convenience in the processing range of ℃ or more. So, is it possible to extend the life by increasing the hardness of the hardness at Shima temperature? 1 elbow heat steel is A2
86 (660 in AI8) has been used and has achieved good results.

And Kerr L, while A286μ active element system Roru T1,
AI 2 many ff! L, further Or 13.5-16
%, CO, 0896, using a mechanical furnace specializing in Arbo/・#lA tax coal method (AOD), vacuum oxygen FIQ coal removal (VOD), and vacuum induction melting@( V
XM) Low 0-Fe-Or and metal Or, which are excellent in furnaces
Use the bow jlllL, you must have Vk4!4il
11 There are major constraints on construction, but there are no additional costs.

[2 Problems to be Solved by the Invention and Means for Solving the Problems] The inventors of the present invention have based on the above-mentioned actual situation, and P! Ifg equipment ft - no need for 4 times! As a result of research to improve the hot work tool steel that can be melted in an air furnace and has performance equivalent to or better than A286 at high temperature 1, the purpose was achieved by using alloy scrap with the composition shown below. It is something that has been learned.

That is, the present invention has a pouch ratio of 00.1 to 0.8%, SIQ,
1-1.5%, Mn 8-30'lx, Or
5-20%.

Ni l -15%1M,)0.1~34j? jhi W0
．． Either one of 1 to 6% is possible, (is both (this is 1.
0.1% MO+ -# (,6%), VO,
2-3%, Nb 0.1-2%, NO, 05-0.
5%, the remainder is Fe J? The gist of the austenitic hot-work tool shoulder is that it has high strength and hardness due to impurities and IJ-like impurities.

[Reason for limitation of I component]

Below, we will discuss the reasons why F Hongenmei Steel's sweat element is limited.

C: C, U-high A is used as a source for precipitation hardening of carbides that improves the hardness, and is used as a source of austenite 1 for Temano A! It is essential. I met up with V for a while and increased my strength by 2 minutes. Therefore, a minimum of 0.14 is required, but 0.
If it exceeds 8chi, forge, machine 1 precept Liloe becomes trouble 4! Since the toughness curve is low F, the upper limit is set at 0.8 inch.

Si: Si is necessary as O and 1% V as a glazing acid cutter, and it can be used as a melting agent, but since it does not contribute to high temperature, the upper limit is 1.5%. do.

Mn: Mn is an austenite stabilizing element with a protective effect. Fuoaki A's 1 [necessary 1 godo element and meguchi N melt] 4 degrees ft increase, F kuma l to 8 fortitude. However, even if it exceeds 30%, you can still see the improvement in Note-4.The upper limit of C1 for Ha is 30 easy.

Cr: Cr is austenite Ti, is a forming element of 1 chuyukachufusuma, and is an o coating element.
It is an essential element to increase Il. It requires 5% as an F1 technique, but if it exceeds 20%, it will be weak and will naturally form, so the upper limit is set at 20.

Ni:Ni is an austenite stabilizing element, which is very important.
Make a charcoal charcoal (himono's anti-expansion charcoal).Therefore, it should contain 1-15 charcoal.

MO, W: MO1way League II [If it is effective with the effect of significantly high N
Minimum 0 for both. Add 1 g. L.

Power・1. Mo oxide has a high vapor pressure, so the upper limit is about 3 yen, and the effect of W 7i becomes saturated, so 6
Let's do it. This is 1. Mo and -W's Katake Kei 1" 0
．． 1% or more and 6% or less.

/: V is soaked with the above-mentioned white C and precipitation hardened L f
Since the il/f warehouse will be raised, 0.2 inch is necessary and the gradient is V20s.
(Nt:Nl) is loosely set at 3 because it has a low melting point and good oxidation resistance.In the case of austenitic alloys, it increases the 14i temperature crimp strength, so it is set at 0.1 for Jt1. do. If the amount exceeds 2%, the effect decreases, so the upper limit is set at 2% gold @N: N is a strong austenitizing element and is used as L-4 to prevent carbonization, causing precipitation hardening. to prevent the precipitation of r-phase. Therefore, the minimum value is set at 0.05, and the upper limit is set at t0.5, because Merugazoeguchi is an internal relative and the effect decreases.

[Explanation of effects from testing]

The following tests were conducted on samples that had been subjected to the following ingredients: milling, forging, stretching, and heat treatment.

1. Ingredients: ○ iji Mn P Ni Cr Mo
V (wt%) t), 54 (1,6715, Q Q
, 0445.1014. %52.3L 1.14Nb
jJ 0.52 1), 319 2, area 1A: 250a→ l zos3, heat treatment:
tzoo℃XI Hr-+w 屹, 720℃X2 Q H
r - + AC 4, test f3 each 2nd, 101st ward withdrawal exam (2) high school 11 (exam, 31 Netsukaku history reading room temperature hard J (exam (4) high temperature creep test 5, test results: exam) This will be explained in comparison with the data of Yukakura A286.

(1) High temperature tensile test results Tensile g1 degree (T, 8 people 0.2 - proof stress (P, day (0,2
Figure 1 shows the measurement results for (related to)). The steel of the present invention is A286
Compared to (aging treatment), the shallowness is lower in the low-temperature area, but when the temperature exceeds 750℃, it becomes VC to discontinue A286. The hardness measurement result of wheat with history added at room temperature and high temperature ICJ is 42
This is shown in Figures 2 and 3 (thermal history theory). In either case, there is no difference compared to A286 at 500°C to 700°C, but Honkomei steel exhibits higher hardness in low-temperature Jdsp machining and high-I crystallization. In particular, when A286 exceeds 700°C, the hardness decreases rapidly, but the steel of the present invention exhibits a small decrease in hardness.

3) Heat history after 4 cycles of hardness l (test results i o o The heat history was given at the valley temperature up to C4, and the theory of cooling to d was supplemented, and the change in hardness was added. The results were $41iJ
+I'', (BJ, No. t). In the pA history of one grade up to 750°C, even at the point Vc2 of n, the steel of the present invention shows a higher hardness, and there is no significant difference in the tendency of hardness j〈5F. 800℃
286 has a large decrease in hardness, whereas the non-inventive steel rod is expected to have high strength at high temperatures without much difference.

+41 Takabatake creep test result 17-7 The test word bundle was adjusted with seesaw/mirror parameters, and the Q was shown in Figure 5.ΦRO 650"C1700'C
Its strength is close to that of A286.

[Example of leprosy]

Based on O-containing i*', A~? The composition system listed in the table is made up of 1, 5 Kf steel ingot melted in a furnace/machinery according to each component,
paojsVcd Nobuyuki. The hardness of these test pieces was determined by heating at dxzou°C x 30', water cooling, and 720Cx20 Hr (D4 effect hardening treatment). All judgments are shown in Tables A to F. Judgment mark X indicates that any one component deviates from the scope of the present invention and is a comparative example.

(below F margin)

[Brief explanation of drawings]

Figure 41 compares the tensile V strength and 0.2 yen yield strength at high temperatures of the present invention steel and A286. Ditch 2. :i! J is a graph comparing the hardness Kt of the invention steel with aging speed and A286 shield temperature ~ 9001G, and the solid line is the hardness curve of the invention steel, and the broken line is the hardness curve of A286 at 66°. is 750'CX300Hr's fever history theory Q
Honsuke Akikuzu and A286's constant! -900'C/c-&-gel hardness ratio 1] In the 2L, 7t graph, solid line 11 is the steel of the present invention, broken line is A286, hardness 1. Figure 4 is a graph showing the change in hardness of barley after 4 cycles of heating at 4 degrees each for 1000 hours and cooling to Changchang.
l-1650℃, (b)V 700℃,
t/l/! At 750 degrees Celsius, -9 is the same as in the heat history of 800 degrees Celsius. In each figure, the broken line shows the hardness of A286, which is almost indistinct steel. ,,g5 Figure 1 U-creep test results organized by r-learn mirror parameters and is a 7t graph. Fig. 1 400 SOD 600 7
00 800 @0 temperature JC) Fig. 2 0 100 200 300 400 500
600 700 800 Li2O; 1 degree (6C) Fig. 3 0 100 200 300 40θ !;Do
600 700 800 '100 1 Ft (
°Cn17!4 Figure

Claims (2)

[Claims] (1) Weight ratio: C0.1-0.8%, Si0.1-1
．． 5%, Mn8-30%, Cr5-20%, Ni1-1
5%, one or both of Mo0.1-3% and W0.1-6% (however, 0.1%<Mo+1/2
W≦6%), V0.2-3%, Nb0.1-2%, N0
．． Austenitic hot work tool steel with excellent high-temperature strength and high-temperature hardness, consisting of 0.05 to 0.5%, the remainder being Fe and unavoidable impurities. (2) A liner material for copper extrusion having the composition according to claim 1.