Stainless Steel AL 17-4™ Precipitation
Hardening Alloy
(UNS Designation S17400)
Data are typical and should not be construed as maximum or minimum values for specification or for final design. Data on any particular piece of ™ Trademark of ATI Properties, Inc.
GENERAL PROPERTIES
Allegheny Ludlum's AL 17-4™ Precipitation Hardening Alloy (S17400), Type 630, is a chromium-nickel-copper precipitation hardening stainless steel ud for applica-tions requiring high strength and a moderate level of corrosion resistance. High strength is maintained to ap-proximately 600°F (316°C).
The S17400 alloy is martensitic in structure in the an-nealed condition and is further strengthened by
a low temperature treatment which precipitates a copper con-taining pha in the alloy. In comparison to many alloys in the precipitation hardening family, the S17400 alloy requires a simple heat treatment; a one step process conducted at a temperature in the range 900°F (482°C)to 1150°F (621°C) depending on the combination of strength and toughness desired. A wide range of prop-erties can be produced by this one step heat treatment.Heat treatment in the 900°F (482°C) range produces highest strength, although slightly less than that of al-loys like S17700 or S15700. The latter precipitation hard-ening alloys generally require more steps to complete heat treatment.
FORMS AND CONDITIONS
The Allegheny Ludlum AL 17-4 Precipitation Hardening Alloy is furnished as plate. Long products are produced by Allvac, an Allegheny Technologies Company. In all forms, the material is furnished in the annealed condi-
tion.
SPECIFICATIONS
The AL 17-4 Precipitation Hardening Alloy (S17400) is covered by the following wrought product specifications.
Data are typical and should not be construed as maximum or minimum values for specification or for final design. Data on any particular piece of Stainless Steel Visit our Website at AL 17-4™ Alloy
CORROSION AND贩的组词
OXIDATION RESISTANCE
Tests have shown that the corrosion resistance of AL 17-4 Precipitation Hardening Alloy is comparable to that of Type 304 stainless steel in most media. In gen-eral, the corrosion resistance of AL 17-4 alloy is supe-rior to that of the hardenable 400 ries stainless steels.As with other precipitation hardening alloys, AL 17-4 Pre-cipitation Hardening Alloy is more susceptible to stress corrosion cracking at peak strength. Conquently, in applications in which chloride stress corrosion cracking is a possibility, the material should be precipitation hard-ened to produce the lowest hardness compatible with the intended end u. This is done by heat treating at the highest temperature which will produce suitable minimum properties.
Material in the annealed condition should not generally be put into rvice. In this condition, the material has an untempered martensite structure and is less ductile than aged material. The untempered martensite may be subject to unpredictable brittle fractures. In corro-sive environments, the untempered martensite is more nsitive to embrittling phenomena such as hydrogen embrittlement than material which has had one of the precipitation hardening heat treatments. Similarly,untempered martensite is more nsitive to chloride stress corrosion cracking than material in which the martensite has been tempered.车站作文
The oxidation resistance of the AL 17-4 alloy is superior to that of 12 percent chromium alloys like Ty泸沽湖草海
pe 410, but slightly inferior to that of Type 430. Precipitation hard-ening will produce surface oxidation.
PHYSICAL PROPERTIES
Technical Data BLUE SHEET
Data are typical and should not be construed as maximum or minimum values for specification or for final design. Data on any particular piece of Room temperature tensile properties can vary substan-tially with heat treatment in the 900°F (482°C) to 1150°F (621°C) range. Values shown below are typical room temperature properties which could be expected for
MECHANICAL PROPERTIES
Stainless Steel AL 17-4™ Alloy
Data are typical and should not be construed as maximum or minimum values for specification or for final design. Data on any particular piece of Stainless Steel Visit our Website at AL 17-4™ Alloy
©
Copyright 2006, Allegheny Ludlum
WELDING AND BRAZING
The AL 17-4 Precipitation Hardening Alloy is readily welded using conventional inert gas methods ud for stainless grades. Preheating is not usually required.Postweld heat treating is needed to produce the vari-ous precipitation hardened heat treatment properties.If matching filler material is ud, properties comparable to tho of the parent metal can be produced in the weld by postweld precipitation hardening heat treatment.When a number of welding pass are made, a sub-stantial thermal cycling has been conducted on the material. More uniform mechanical properties can be obtained by solution annealing the material before con-ducting precipitation hardening heat treatments. The solution anneal has the effect of minimizing the effects of the thermal cycling.
In the ca of welding with non-matching filler, an aus-tenitic stainless steel such as 308L or other ductile aus-tenitic should be ud. This filler will not produce the precipitation hardening respon, however.
共同共有房产HEAT TREATMENT
The AL 17-4 Precipitation Hardening Alloy is furnished in the annealed condition. This is also called the solu-tion heat treated condition, or Condition A. Annealing is conducted by heat treating at appro
ximately 1900°F (1040°C) to 1950°F (1065°C) and cooling to room tem-perature. In this condition, the material posss a martensitic structure. As a martensitic structure, the AL 17-4 alloy posss a relatively high strength and hardness in the annealed condition. The strength and hardness of the material is generally somewhat lower in the H 1150 overaged condition.
同济会
To develop further increa in strength, the annealed material is precipitation hardened by heat treatments at 900°F (482°C). Heat treatments above 1075°F (579°C)generally result in material softer than material in the annealed condition. The heat treatments are usually specified as follows:
骆驼祥子读书笔记200字The precipitation hardening reaction can be driven past peak strength by heat treating at an excessively high temperature or by excessive time at the precipitation hardening temperature. The table on page 3 shows the effect of higher temperature heat treatment. A less dra-matic downward shift in strength results from excessively long precipitation hardening times.
The heat treatments ud for the AL 17-4 Precipitation Hardening Alloy are summarized below.
FORMING
半夏的功效The tensile data for the AL 17-4 Precipitation Hardening Alloy indicate that the alloy does not poss
s the high tensile elongation characteristic of the austenitic stain-less steels. The material is capable of being mildly formed but is not capable of being verely formed.Forming is more easily accomplished in the overaged (such as H 1150-M from SA 693) condition than in the annealed, condition.
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