Alternative to stainless steel shot blast media

A. You didn't spell out if you are using a uniform SS shot or a grit; however, it would be very difficult to reproduce the same results using a different blast media because of the weight factor. Most people use steel media to not only clean a work surface, but to work harden that surface. Therefore, without multiple passes using another media like glass beads, you are not going to reproduce the same exact results.

A. Glass beads, Ceramic balls, etc are available for shot blasting. But I must agree that the finish you would get from these medias will not be the same as S.S. media.

A. Dear Aaron,

The finish with stainless steel shot is depending on the grade and as mentioned already on the shape and consistency of the particles. Most aggressive is a stainless steel grit ( there are three suppliers on the market with three different grades ) next would be stainless steel cut wire AISI 420J -which has a constant hardness of 64 HRC and best ratio performance / price in this class of media !

next would be :

AISI 301 ( Best performance and durability ) - - AISI 302 ( best ratio performance / price ) AISI 304 Stainless steel shot ( atomized shot available from at least 7 independent manufacturer made in : USA ITALY GERMANY( 2) SOUTH AFRICA, CHINA (4!)

AISI 430 Cut Wire with best price / performance ration for shot blasting, deburring & deflashing any kind of Al- Castings ( from Sand over permanent mold to Pressure die casting ) in the size range 0.355 mm - 1.5 mm ( 0.014 - 0.049 ") This material does have no or very low content on Nickel and will be the future media for such application due to environmental restriction and the rising cost for Nickel )

This material does not pick up hardness due to plasticity induced martensitic transformation. This is resulting in very constant shot blasting condition. A mix of AISI 430 cut wire and Alumina Zirconia - in the right size mix ! ) will result in a very glossy finish on stainless steel parts that need to be cleaned from discoloration of slight heat scale due to welding.

So long,

A. Probably the reason your organization removes scale by pickling is because it is inexpensive. However, if cost is no object, grit blasting gives excellent results. I'd recommend hardened steel grit - it is inexpensive compared to stainless, has much more weight than ceramic or glass, and has hard sharp edges. 'You pays your money and you takes your choice.' (As Mark Twain said unoriginally in Huckleberry Finn.)

A. Hi Ekam. To my knowledge unheated sulfuric acid is not an effective pickling agent. If you will be staying with sulfuric acid instead of moving to hydrochloric acid, I think you'll need to heat it. Please see letters 58440 & 12028 and the article "The Kleingarn Regenerated Spent Acid ... " in our on-line library because it's not just a simple matter of what percentage of acid to employ; rather, inhibitors, acid-extenders, and metal concentration are all part of the equation.

Regards,

A. In regards to "what acid concentration" or "what alternative method" to use for pickling, really the answer is whatever works.

Pickling as a term just means acid descaling. Descaling just means "get the ugly off so it looks nice". Any method you find that achieves that purpose (and doesn't create any unseen damage) is a viable process. (Which of multiple viable processes is "better" depends on cost, hazards, etc.)

To the question of "Will descaling method/parameters X work for material Y?" the answer depends on what you fill in those blanks with. Industry standards and such often give known working methods and parameters for specific materials. Otherwise, I like the old standard "Try it and see!"

A. Ekam Singh,
Unless I'm misunderstanding, the acid doesn't care what the diameter of the rods is.