ASTM B600-22

Standard Guide for Descaling and Cleaning Titanium and Titanium Alloy Surfaces

ABSTRACT
This guide covers a cleaning and descaling procedure useful to producers, users, and fabricators of titanium and titanium alloys for the removal of ordinary shop soils, oxides, and scales resulting from heat treatment operations and foreign substances present as surface contaminants. It is recommended that the materials shall be subjected to soil removal prior to heat treatment or application of acid treatment. Mechanical descaling methods such as sandblasting, shot blasting, and vapor blasting may be used to remove hot work scales and lubricants from titanium surfaces. Recommended post treatment of shot or abrasive blasted titanium surfaces may include acid pickling to ensure complete removal of surface contaminants. For chemically milled materials, salt bath conditioning may be required to remove the oxygen-contaminated layer. Acid etching treatment may be required following mechanical abrading or chemical conditioning of materials to completely clean the surface.
SCOPE
1.1 This guide covers a cleaning and descaling procedure useful to producers, users, and fabricators of titanium and titanium alloys for the removal of ordinary shop soils, oxides, and scales resulting from heat treatment operations and foreign substances present as surface contaminants.  
1.2 It is not intended that these procedures be mandatory for removal of any of the indicated soils but rather serve as a guide when titanium and titanium alloys are being processed in the wrought, cast, or fabricated form.  
1.3 It is the intent that these soils be removed prior to chemical milling, joining, plating, fabrication, and in any situation where foreign substances interfere with the corrosion resistance, stability, and quality of the finished product.  
1.4 Acid etching may be required following cleaning when the surface has an oxygen-contaminated layer or alpha case present.  
1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2022
• ICS: 77.150.50 - Titanium products
• Technical Committee: B10 - Reactive and Refractory Metals and Alloys
• Drafting Committee: B10.01 - Titanium

Overview

ASTM B600-22 is the Standard Guide for Descaling and Cleaning Titanium and Titanium Alloy Surfaces, developed by ASTM International. This guide outlines recommended practices for the effective removal of shop soils, oxides, heat treatment scales, and foreign surface contaminants from titanium and titanium alloys. It provides essential procedures for ensuring the quality and corrosion resistance of titanium materials used in various industries. The standard is particularly valuable for producers, users, and fabricators of both wrought, cast, and fabricated titanium products.

Key Topics

• Cleaning and Soil Removal: Emphasizes the importance of removing shop soils, grease, oil, and lubricants from titanium surfaces. Alkaline or emulsion soak cleaners and electrolytic alkaline cleaning systems are recommended prior to any heat or acid treatments.
• Mechanical Descaling: Methods such as sandblasting, shot blasting, and vapor blasting are suitable for removing hot work scales and lubricants. Selection of media and process controls are important to prevent contamination or unwanted surface roughening.
• Post-Blast Conditioning: Acid pickling is recommended following abrasive cleaning to ensure complete removal of residual contaminants, especially embedded steel particles or interstitial elements.
• Chemical Conditioning and Pickling: Includes processing steps such as salt bath conditioning and acid etching for the removal of oxygen-contaminated layers or "alpha case" that can form during high-temperature treatments.
• Inspection and Quality Control: Visual inspection, hydrogen content monitoring, and optional chemical milling are advised to verify cleanliness, with quality checks ensuring that surfaces are free from paint, oil, glass, graphite, iron, and other residues.
• Safety and Environmental Considerations: Users are responsible for implementing appropriate safety, health, and environmental practices when following this guide.

Applications

• Aerospace Manufacturing: Ensures high-purity titanium surfaces for structural components, where corrosion resistance and surface integrity are critical.
• Medical Device Production: Supports the stringent cleaning of titanium for biomedical implants and devices, enhancing biocompatibility and patient safety.
• Chemical Processing Equipment: Provides guidance for cleaning titanium reactors, vessels, and piping, maintaining resistance to harsh chemical environments.
• Automotive and Marine Uses: Ensures surface stability and performance of titanium parts exposed to demanding operational conditions.
• Fabrication and Finishing: Advises on proper cleaning before downstream operations such as chemical milling, joining, plating, or final fabrication, which may be adversely affected by surface contamination.

Related Standards

• ASTM B348 - Standard Specification for Titanium and Titanium Alloy Bars and Billets
• ASTM E34 - Standard Test Methods for Chemical Analysis of Titanium and Titanium Alloys
• ASTM E1447 - Standard Test Method for Hydrogen in Titanium and Titanium Alloys by Inert Gas Fusion Thermal Conductivity/Infrared Detection
• ASTM F86 - Standard Practice for Surface Preparation and Marking of Metallic Surgical Implants

Summary

By following ASTM B600-22, organizations can maintain the quality, corrosion resistance, and surface stability of titanium and titanium alloy products. Adherence to this guide minimizes the risk of contamination, ensures reliable downstream processing, and supports compliance with rigorous industry standards for critical applications. Employers and operators are encouraged to consult the most current version of this standard and implement best practices for both safety and technical performance.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B600 − 22
Standard Guide for
Descaling and Cleaning Titanium and Titanium Alloy
Surfaces
This standard is issued under the fixed designation B600; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Processing Soil Removal
1.1 This guide covers a cleaning and descaling procedure 2.1 It is recommended that grease, oil, and lubricants
useful to producers, users, and fabricators of titanium and employedinmachining,forming,andfabricatingoperationson
titanium alloys for the removal of ordinary shop soils, oxides, titanium and titanium alloys be removed by alkaline or
and scales resulting from heat treatment operations and foreign emulsion soak-type cleaners and electrolytic alkaline cleaning
substances present as surface contaminants. systems. In the electrolytic system the work may be either
anodic or cathodic polarity. Removal of these soils is recom-
1.2 It is not intended that these procedures be mandatory for
mended prior to heat treatment or application of acid treatment
removal of any of the indicated soils but rather serve as a guide
designated in 4.2.When electrolytic systems are employed, the
when titanium and titanium alloys are being processed in the
voltage should be controlled to prevent the occurrence of spark
wrought, cast, or fabricated form.
discharge and subsequent pitting.
1.3 It is the intent that these soils be removed prior to
chemical milling, joining, plating, fabrication, and in any
3. Blast Cleaning
situation where foreign substances interfere with the corrosion
3.1 Mechanical descaling methods such as sandblasting,
resistance, stability, and quality of the finished product.
shot blasting, and vapor blasting may be used to remove hot
1.4 Acid etching may be required following cleaning when
work scales and lubricants from titanium surfaces if followed
the surface has an oxygen-contaminated layer or alpha case
by thorough conditioning and cleaning as described in Section
present.
4.
1.5 The values stated in inch-pound units are to be regarded
3.2 The sand used for blasting should be a high-grade,
as standard. The values given in parentheses are mathematical
washed, iron-free, silica sand or other ceramic media. If carbon
conversions to SI units that are provided for information only
or low-alloy steel products are sandblasted in the same facility,
and are not considered standard.
thesandusedforcleaningtheseproductsshouldnotbeusedon
titanium surfaces and a separate sand supply should be
1.6 This standard does not purport to address all of the
provided.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.3 Roughening of exposed surface areas may occur from
priate safety, health, and environmental practices and deter-
grit or shot if cleaning of the entire surface is accomplished by
mine the applicability of regulatory limitations prior to use.
blasting. Partial cleaning for preserving the surface finish is to
1.7 This international standard was developed in accor-
be preferred in conjunction with proper pickling procedures.
dance with internationally recognized principles on standard-
3.4 Blast cleaning that utilizes steel grit, steel shot, or sand
ization established in the Decision on Principles for the
containing appreciable amounts of iron should be followed by
Development of International Standards, Guides and Recom-
acid pickling to remove any embedded steel particles on the
mendations issued by the World Trade Organization Technical
surface of the titanium.
Barriers to Trade (TBT) Committee.
3.5 Any abrasive or shot blast cleaning may induce residual
compressive stresses in the surface of the material or titanium
structure. Warpage may occur in thinner sections that are
This guide is under the jurisdiction ofASTM Committee B10 on Reactive and
subsequently chemical milled or contour machined.
Refractory Metals and Alloys and is the direct responsibility of Subcommittee
B10.01 on Titanium.
3.6 In most cases, blast cleaning is not intended to eliminate
Current edition approved Oct. 1, 2022. Published October 2022. Originally
pickling procedures completely. Abrasives will not remove
approved in 1974. Last previous edition approved in 2017 as B600 – 11 (2017).
DOI: 10.1520/B0600-22. surface layers contaminated with interstitial elements such as
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B600 − 22
NOTE 3—Silicon-based protective coatings used to minimize scale
carbon, oxygen, and nitrogen.When these elements are present
formation during hot forming or annealing of titanium alloys are soluble
in excessive amounts, they are preferably removed by con-
in the molten salt bath.All of the coating should be removed prior to any
trolled acid pickling in accordance with 4.3.
acid treatment.
4. Pickling, Cleaning, and Descaling
4.3 Following mechanical abrading or chemical
conditioning, the material may be further treated to completely
4.1 Recommendedposttreatmentofshotorabrasiveblasted
clean the surface in one of the following solutions:
titanium surfaces may include acid pickling as described in
4.3.2, or acid cleaning as described in 4.3.3. If the product is to 4.3.1 After salt bath conditioning and water rinse, the
titanium or titanium alloy may be immersed in a sulfuric acid
be chemical milled for the removal of the oxygen-
contaminated layer, salt bath conditioning may be used, or solution to remove the converted scale product. It is recom-
mended that the acid solution be maintained at 150 °F (66 °C)
required, in order to avoid selectively etched surfaces if
configuration interferes with uniform blasting. and a concentration of 10 to 40 volume % of sulfuric acid
(95 % solution by weight). Final brightening may be accom-
4.2 Scale and lubricant residues developed on mill, foundry,
plished by a short immersion in the acid solution of 4.3.2.
forged, or fabricated titanium products usually require condi-
4.3.2 To ensure complete removal of metallic iron, oxide,
tioning by one of the following commercial methods prior to
scale, and other surface contaminants, material that has been
final pickling as described in 4.3.2 to produce a completely
mechanically abraded in accordance with 3.1 or chemically
scale-free surface.
conditioned in accordance with 4.2.1, 4.2.2,or 4.2.3 may be
4.2.1 Proprietary solutions of caustic-based compounds in
finish cleaned by immersion in an acid solution composed of
tap water in accordance with the manufacturer’s recommenda-
10 to 30 volume % (150 to 450 g/L) of nitric acid (70 %) and
tion.
1 to 3 volume % (12 to 36 g/L) of hydrofluoric acid (60 %) at
4.2.2 Molten alkaline-based salt baths operating at 750 to
120 °F (49 °C), maintaining a ratio of 10 parts nitric acid to 1
850 °F (399 to 454 °C) in accordance with prescribed proce-
part hydrofluoric acid.
dures.
4.2.3 Molten alkaline-based salt baths operating at 400 °F
NOTE 4—Hot-formed or heat-treated titanium fabrications or assem-
(204 °C) in accordance with prescribed procedures.
blies that have a mixed surface contamination consisting of graphite or
molybdenum disulfide with titanium oxides should be condition
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B600 − 11 (Reapproved 2017) B600 − 22
Standard Guide for
Descaling and Cleaning Titanium and Titanium Alloy
Surfaces
This standard is issued under the fixed designation B600; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This guide covers a cleaning and descaling procedure useful to producers, users, and fabricators of titanium and titanium alloys
for the removal of ordinary shop soils, oxides, and scales resulting from heat treatment operations and foreign substances present
as surface contaminants.
1.2 It is not intended that these procedures be mandatory for removal of any of the indicated soils but rather serve as a guide when
titanium and titanium alloys are being processed in the wrought, cast, or fabricated form.
1.3 It is the intent that these soils be removed prior to chemical milling, joining, plating, fabrication, and in any situation where
foreign substances interfere with the corrosion resistance, stability, and quality of the finished product.
1.4 Acid etching may be required following cleaning when the surface has an oxygen-contaminated layer or alpha case present.
1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to consult and establish appropriate safety safety, health, and healthenvironmental practices and
determine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Processing Soil Removal
2.1 It is recommended that grease, oil, and lubricants employed in machining, forming, and fabricating operations on titanium and
titanium alloys be removed by alkaline or emulsion soak-type cleaners and electrolytic alkaline cleaning systems. In the electrolytic
system the work may be either anodic or cathodic polarity. Removal of these soils is recommended prior to heat treatment or
application of acid treatment designated in 4.2. When electrolytic systems are employed, the voltage should be controlled to
prevent the occurrence of spark discharge and subsequent pitting.
This guide is under the jurisdiction of ASTM Committee B10 on Reactive and Refractory Metals and Alloys and is the direct responsibility of Subcommittee B10.01
on Titanium.
Current edition approved May 1, 2017Oct. 1, 2022. Published May 2017October 2022. Originally approved in 1974. Last previous edition approved in 20112017 as
B600 – 11.B600 – 11 (2017). DOI: 10.1520/B0600-11R17.10.1520/B0600-22.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B600 − 22
3. Blast Cleaning
3.1 Mechanical descaling methods such as sandblasting, shot blasting, and vapor blasting may be used to remove hot work scales
and lubricants from titanium surfaces if followed by thorough conditioning and cleaning as described in Section 4.
3.2 The sand used for blasting should be a high-grade, washed, iron-free, silica sand. sand or other ceramic media. If carbon or
low-alloy steel products are sandblasted in the same facility, the sand used for cleaning these products should not be used on
titanium surfaces and a separate sand supply should be provided.
3.3 Roughening of exposed surface areas may occur from grit or shot if cleaning of the entire surface is accomplished by blasting.
Partial cleaning for preserving the surface finish is to be preferred in conjunction with proper pickling procedures.
3.4 Blast cleaning that utilizes steel grit, steel shot, or sand containing appreciable amounts of iron should be followed by acid
pickling to remove any embedded steel particles on the surface of the titanium.
3.5 Any abrasive or shot blast cleaning may induce residual compressive stresses in the surface of the material or titanium
structure. Warpage may occur in thinner sections that are subsequently chemical milled or contour machined.
3.6 In most cases, blast cleaning is not intended to eliminate pickling procedures completely. Abrasives will not remove surface
layers contaminated with interstitial elements such as carbon, oxygen, and nitrogen. When these elements are present in excessive
amounts, they are preferably removed by controlled acid pickling in accordance with 4.3.
4. Pickling, Cleaning, and Descaling
4.1 Recommended post treatment of shot or abrasive blasted titanium surfaces may include acid pickling as described in 4.3.2,
or acid cleaning as described in 4.3.3. If the product is to be chemical milled for the removal of the oxygen-contaminated layer,
salt bath conditioning may be required used, or required, in order to avoid selectively etched surfaces if configuration interferes
with uniform blasting.
4.2 Scale and lubricant residues developed on mill, foundry, forged, or fabricated titanium products usually require conditioning
by one of the following commercial methods prior to final pickling as described in 4.3.2 to produce a completely scale-free surface.
4.2.1 Proprietary solutions of caustic-based compounds in tap water in accordance with the manufacturer’s recommendation.
4.2.2 Molten alkaline-based salt baths operating at 750 to 850°F850 °F (399 to 454°C)454 °C) in accordance with prescribed
procedures.
4.2.3 Molten alkaline-based salt baths operating at 400°F (204°C)400 °F (204 °C) in accordance with prescribed procedures.
4.2.4 Oxides and heat tints developed below 1100°F (593°C)1100 °F (593 °C) can frequently be removed by pickling in an acid
solution composed of 10 to 20 volume % (150 to 300 g/L) of nitric acid (70 %) and 1 to 2 volume % (12 to 24 g/L) of hydrofluoric
acid (60 %) at 120°F (49°C).120 °F (49 °C).
4.2.5 Forged and hot-worked titanium alloys that have the normal heat-developed scale mixed with graphitic or glass-type
lubricants may be conditioned in a molten alkaline-based salt bath operating at 850°F (454°C)850 °F (454 °C) to effect complete
solubility of the complex scale. Following conditioning, the part should be pickled as described in 4.3.2.
4.2.6 It is recommended that heat-treatable alpha beta and beta alloys in the solution-treated condition that have been processed
at temperatures above 1100°F (593°C),1100 °F (593 °C), with graphitic and molybdenum disulfide lubricant residues mixed with
the heat-developed scale, be conditioned in a molten alkaline-based salt bath operating at 400°F (204°C).400 °F (204 °C). After
conditioning, the part may be pickled in accordance with the treatment described in 4.3.2.
4.2.7 Abrasive methods such as wheel or belt grinding, segmented flapper wheels, and grit or shot blasting, when available, may
be used when surface configuration is such that the scaled areas are readily accessible.
NOTE 1—Conditioning of titanium in high-temperature oxidizing salt can generate galvanic currents where the work is contacting ferrous base materials.
...