Supplement to A.S.T. M. Methods of Chemical Analysis of Metals.—These methods are a revision of and supersede the former Tentative Methods of Sampling Ferro-Alloys iA 103 -36 T) which latter methods appear on pages 54 to 57 of the Society's publication "A.S.T. M. Methods of Chemical Analysis of Metals " 1936 i." Since these methods replace the former Tentative Methods A 103 - 36 T, this copy should be substituted in the compilation of the Metti"jd£ of Chemical Analysis of Metals.
Ten ta five* Methods of"'1 •
A.S.T. M. Designation: E 32-39 T
This Tentative Standard of the American Society for Testing Materials is, under its Regulations, subject to annual revision. Suggestions for revision should be addressed to the Society, 260 S. Broad St., Philadelphia, Pa.
'. These methods include procedures for the sampling of the various ferro-alloys, either before or after shipment from the plants of the manufacturers. They are designed to give results representative of each' lot that will be comparable with the tnanufacturer's guaranteed analysis for the same lot. For check analysis, the -.purchaser may use any sampling procedure he desires, but the analytical results obtained on such samples shall not be a basis for complaint or rejection, unless the procedure followed is of an accuracy equivalent to that prescribed in these methods.
In sampling ferro alloys, serious errors often occur from contamination of the samples by iron from the sampling appliances. Therefore, special precautions should be observed to avoid this source -of error. Metallic iron may be removed with a magnet from non-magnetic allovs; uS estimation in other allovs requires
1 Urtder the standarduanor. pro. edao these methods are under the iurisdn lion
- These t:.l-1:. .ds ave i-. -dm-.: a rem.. the forme Tentative Methods o: s Ailo;. $ (A l'ö - So 'id waa h u-.;rt pm h^ed a" tentative from 1023 'o adopted as standard in !'07, mit
N -prifchdraavi-. an.1, repiddished as ter.ative fron-, 19.16 to
epted for publiaation as tentative bv Committee on Standards, Mar. h 4. 1W.
special analytical procedures.3 To avoid this error, parts of crushers and pulverizing equipment contacting the samples shall be of steel or other material showing a high resistance to abrasion of the type involved.
Apparatus tor Preparing Samples
The following equipment is required for the preparation of analytical samples of ferro-alloys:
Crusher.—A strongly built jaw crusher capable of rapidly crushing 1-in. lumps to sizes ^-in. and smaller shall be used. The crushing plates of this machine shall be made of a hard and abrasion-resistant steel, such as manganese steel or a properly hardened alloy or hypereutectoid carbon steel.
Roll Crusher.—A roll crusher, the rolls of which are lilted with tires of hardened and tempered chromium steel to avoid
Metahi.. m 1 er:odiiua ]n:r, and rirrosihron may : e rcTer-- med as mmo-vs: Transler .a c of the samp'e oi .-.'lov to a lao-ma ! cake-, add 23 ml. of diluted 1I-MJ:, if,,, irr. 1.1.«.■.(,•, over. oil. 5 mm., niter into a e * "ate- Add
lit lü t'tei-, and
tv..m v.ito mat v.o.ier. aJm-...e toe ore.ipnate on Tat papor v.-'.ln a mmiimam ommlnv Ol ..ot üihited H'. ", wash t!ie niter witn cat water, and titrate tit iron ov a standard procedure. Multiply the iron value or ti.e total numher of milliliters ot titrating soh tion used by 100 and divide lay 5 to find the percentage of" metallic iron.