13-8Mo Semi Product Special Alloys For Aerospace And Defense With Good Toughness

Alloy 13-8Mo (UNS S13800) semi-product for machined fastener, shafts, landing gear part, pin, lockwasher, etc.

1 PRODUCT

Alloy 13-8Mo (UNS S13800) semi-product for machined fastener, shafts, landing gear part, pin, lockwasher, aircraft component etc.

Alloy 13-8Mo is available in following standard semi-finished forms:

Bar and Rod

Delivery condition: Forged, rolled, drawn, heat treated, oxidized, descaled or pickled, turned, peeled, ground or polished

Shape and profile

Rolled and extruded, cold drawn, oxidized, descaled or pickled

Wire (profile, round, flats, square)

Delivery condition: Drawn bright, ¼ hard to hard, bright annealed in rings, containers, on spools and headstocks

Wire rod

Delivery condition: hot rolled (dia.5.5mm to 40mm)

Others

Other shapes and dimensions such as discs, rings, seamless pipes, fasteners and forgings can be requested.

2 EQUIVALENT DESIGNATION

UNS S13800, XM-13, PH 13-8Mo, ATI 13-8^TM

3 OVERVIEW

UNS S13800 is a precipitation hardening martensitic stainless steel that combines excellent strength, good toughness, and good general corrosion resistance. It is a through-hardening alloy, which allows it to be used in parts with large cross sections, where yield strengths in excess of 200 ksi (1380 MPa) may be required. Good transverse toughness properties are achieved by tight chemical composition control (to prevent the formation of delta phase), low carbon content (to minimize grain boundary precipitation), and double vacuum melting (to reduce alloy segregation). Since the rate of cooling from the solution temperature is not critical, large cross sections can be air-cooled.

This alloy is produced by a primary vacuum induct ion melt process (VIM), followed by a consumable vacuum arc remelting (VAR) step. Or followed by electro-slag remelting (ESR). These melt practices promotes excellent macro and micro cleanliness, and tight compositional control. The strengthening mechanism (precipitation hardening in a martensitic matrix) makes it possible to achieve uniform strengthening in heavy sections. Strength and ductility levels can be tailored to the application by varying the aging temperature.

4 APPLICATION

UNS S13800 stainless has been used for valve parts, fittings, cold-headed and machined fasteners, shafts, landing gear parts, pins, lockwashers, aircraft components, nuclear reactor components and petrochemical applications requiring resistance to stress-corrosion cracking. Generally, this alloy should be considered where high strength, toughness, corrosion resistance, and resistance to stress-corrosion cracking are required in a steel showing minimal directionality in properties.

Typical uses of the alloy bar are aircraft parts, rocket engine mounts, nuclear reactor parts, landing gear components, high performance shafts, and petrochemical parts that require high strength combined with good resistance to stress corrosion.

Typical applications of the alloy plate are large airframe structural components, injection molding equipment and slide gates to control water flow.

5 CHEMICAL COMPOSITION (wt%):

6 PHYSICAL PROPERTY

Melting range:2560 - 2680ºF (1405 - 1470ºC)

Density: 0.279 lb/in³ (7.76 g/cm³)

Thermal conductivity 212°F, Condition A: 97.20 BTU-in/hr/ft²/°F

Elastic Modulus: 73°F, Condition H 1000, Longitudinal: 28.3 x 10³ ksi

7 MECHANICAL PROPERTIES

Strength varies with heat treatment condition. The following table shows minimum mechanical properties for the various aged conditions, per AMS 5864. Subsequent figures show typical data

Hardness

Hardness in the solution annealed condition is approximately Rockwell C 33. See the attached table for hardness in the various aged conditions.

8 CORROSION RESISTANCE

UNS S13800 alloy has excellent oxidation resistance up to 1500ºF (816ºC). Corrosion resistance decreases slightly as the aging temperature is raised. This alloy has the best resistance to stress corrosion cracking of all of the precipitation hardenable stainless steels. Its resistance to general corrosion is greatest in the fully-hardened condition. The alloy shows very little rusting when exposed to a 5 percent salt fog at 95ºF (35ºC).

9 WORKING INSTRUCTION

UNS S13800 stainless has good fabrication characteristics and can be age-hardened by a single low temperature treatment. Cold work prior to aging increases the aging, especially for lower aging temperatures.

Hot working

UNS S13800 stainless can be readily forged, hot headed and upset. Material which is hot-worked must be solution treated prior to hardening if the material is to respond properly to hardening.

Forging

UNS S13800 alloy has good hot working characteristics, and can be forged over a wide temperature range. Temperatures up to 2200°F (1204ºC) may be used. For optimum properties, forging temperature should not exceed 1900ºF (1038ºC). Hot working should not be done below 1700ºF (927ºC). After forging, parts should be cooled to room temperature, then solution treated prior to aging.

Cold forming

The alloy can be cold formed in the annealed condition, utilizing conventional cold forming techniques.

Heat treatment

The S13800 alloy is martensitic in structure in the solution annealed condition and is further strengthened by a relatively low temperature heat treatment, which precipitates a strengthening phase in the alloy. Like the S17400 alloy, the S13800 alloy requires only a simple heat treatment, a one step process conducted at a temperature in the range 950°F (510°C) to 1150°F (620°C) depending on the combination of strength and toughness desired. A wide range of properties can be produced by this one step heat treatment. Heat treatment at about 950°F (510°C) produces the highest strength.

10 STANDARD SPECIFICATION

AMS 5629 Bars, forgings, rings, and extrusions

AMS 5864 Plate

ASTM A564 / ASME SA564 (Grade XM-13) Bars, wires and shapes

ASTM A693 / ASME SA693 (Grade XM-13) Sheet, plate and strip

ASTM A705 / ASME SA705 (Grade XM-13) Forgings

MIL-S-2154

11 COMPETITIVE ADVANTAGE:

(1) More than 50 years experience of research and develop in high temperature alloy, corrosion resistance alloy, precision alloy, refractory alloy, rare metal and precious metal material and products.
(2) 6 state key laboratories and calibration center.
(3) Patented and innovative technologies.

(4) Ultra-purity smelting process: VIM + IG-ESR + VAR

(5) Excellent high performance.

12 BUSINESS TERM