The steels of that era are highly variable due to the inability of steel makers to identify, test, and remove none oxidizing elements. The processes of the era were very simple metallurgical processes.
Residual Elements in Steel
https://www.totalmateria.com/page.aspx?ID=CheckArticle&site=kts&NM=205
Abstract:
Residual elements (Cu, Ni, As, Pb, Sn, Sb, Mo, Cr, etc.) are defined as elements which are not added on purpose to steel and which cannot be removed by simple metallurgical processes. The presence of residual elements in steel can have strong effects on mechanical properties. There is therefore clearly the need to identify and to quantify the effects of residual elements in order to keep these effects within acceptable limits.
Since so much scrap is recycled in the making of steel, “tramp elements” are a major concern.
https://www.tms.org/pubs/journals/jom/0110/manning-0110.html
One alternative to removing metallic tramp elements is to reduce their deleterious effects on steel properties. Most metallic residuals reduce steel hot strength and hot and cold ductility by segregating to and weakening grain boundaries. Tolerance to such chemical impurities could be improved through the design of alloys in which these elements were tied up in heterogeneously nucleating second-phase particles, which might not have the same negative effect on steel properties. Also, new near net shape casting processes, which will be described in following sections, may dramatically reduce the overall effect of residual elements for two reasons. As its name implies, near net shape casting describes solidification processes by which steel is cast in dimensions near to the specifications of the final product.
Might also look at the problem of micro inclusions and how they weaken steels.
Designers today, use data supplied by steel manufacturers, who test and provide the mechanical properties of their steels. Some questions I have, and would like to know, just what standards were being used in the 1890’s and when did the definitions of yield, ultimate baselined? Today, we are aware of the effect of low temperature on steel properties. From my reading, fatigue lifetime was unknown around World War 1, and so was knowledge about low temperatures and brittleness. I read that the first phase diagrams were came out in the 1890’s. And, in that time period, what mechanical properties were steel manufacturer’s reporting? I would like to know that, I do have a first edition of Machinery’s Handbook, (1916) I can tell you, there are serious gaps in the metallurgical knowledge of the period. The section on the heat treatment of carbon and alloys goes from Heat treatment A to heat treatment U. Actually not bad advice for the simple steels of the era. There is no reference to a steel specification such as SAEXXXX. Those standards came later. Specific “high speed tool” steels are referred to by maker, such as Burgess, Rex High Speed, Bethlehem self hardening. No compositional or material data is given on those high speed steels, just heat treatment suggestions. Anyone who spends any time looking at 19th century metallurgy, and knows what is available today, will see large gaps in period knowledge and technology.
Bessemer created a blast furnace technology that vastly increased the rate of steel production over any previous process, but he used Swedish iron. Swedish iron, by an accident of geology, is low in phosphors. Apparently Bessemer did not know that, but his licensee’s were using cheaper iron ores which were high in phosphorus and their steels were brittle. And they were suing. Bessemer found a chemist who created spiegeleisen
https://en.wikipedia.org/wiki/Spiegeleisen which removed the phosphorus. But you know, the Bessemer process, and all those early processes, could not remove non oxidizing elements.
There is some data out there on WW1 era Mauser actions.
http://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/4281076061?r=8481020161
The following was the steel composition specified by the Mausers, from page 103
Rifle & Carbine 98: M98 Firearms of the German Army from 1898 to 1918 Dieter Storz
Carbon LT 0.40%
Manganese LT 0.90%
Copper LT 0.18%
Silicon LT 0.30%
Phosphorous LT 0.04%
Sulphur LT 0.06%
When you compare what was the desired composition, against what was coming out of the mill, it is evident there is a lot of residual elements in the compostion. The material used in Mausers looks to be a manganese steel alloy. The copper is most likely a contaminant, with a percentage to limit the amount, it could be that copper added for easy machining, either way, it detracts from the steel properties. Specified property requirements were: Ultimate 78.2 Ksi, Yield 36.9 KSI
, elongation 15%. A yield under 40 KSI probably means these are the desired properties of normalized steel.
Silicon, phosphorous and sulphur were actually undesirable, but unavoidable based on the ladle linings, so the percentages are limited. The load imparted to the lugs and the receiver seat is an impact load. Phosphorous has the ability to increase steel strength, hardness, and hardenability, but, sulphur and phosphorous adversely affect the material’s toughness, fatigue strength, which are critical properties in a rifle receiver. The other stuff, in the assay, is crap. To repeat, this stuff is crap that got into the steel. That nickel, chromium, molybdenum, vanadium, columbium, are all containments. Instead of making this some super duper advanced alloy steel, these “residuals” unpredictably detract from the properties of the steel.
These residuals are elements that the Bessemer and Open Hearth processes were not able to oxidize during the oxygen blow. They come from multiple sources, the most common one in today’s world, is scrap. Scrap is often contaminated with coatings of various kinds, and there is nothing to indicate that the steel manufactures were particular about the segregation of scrap. They might have been tossing everything and anything into the ladle. Waste in steel plant was collected and thrown back into the process, which also gave a slow but steady increase in the residual content, especially of copper and nickel, as these elements are not oxidized and removed in steel making.
So, given the unknown quality of the steels of the 1890's, as much as the machining looks great, the steels are going to be weaker than the same stuff used today.
This is from a paper by Bain, in the 1920’s. This paper was referenced in a post WW2 metallurgical book, and the author was making the case that plain carbon steels, which were the type of steels used in Krag’s, Mausers, M1903’s, heat treat erratically. Post WW2 (I don’t have the WW2 version) these plain carbon steels are being called shallow hardening. The graph to the right shows hardness by depth with these plain carbon steels. And, the hardness depth is varying, and not consistent through the coupon.
View attachment 1059171
Bain, and this is the Bain of whom Bainite is named, took identical sections of plain carbon steels, placed a selection in a heat treat oven, and acid etched the finished products. Bain showed that given identical plain carbon steel, in the same heat treat oven, specimens varied in heat treatment depth. The dark parts show the amount of steel that did not harden. This variability was more or less eliminated by alloy steels, which hardens deeply and consistently. This is a real concern as unless the part is completed hardened, it won’t hold a load as designed.
So, given the unpredictable and varying composition of these early steels, and then the tendency of the steel to harden erratically, these early steels are inferior in all respects to the same steels today.
I have gone through modern metallurgy books, and this cautionary tale told to the WW2 generation is missing. Science advances one funeral at a time and I think those who were pathologically attached to plain carbon steels, and shunned alloy steels, are gone. So a section on the advantages and superiority of alloy steels over plain carbon steels is no longer needed. But there was a time when the case had to be made.
I remember the period when calcified engineers were called “slide rule” engineers.
View attachment 1059172
I can still use the C/D scales on my slide rule. Purchased it new from the College Bookstore. There used to be a wonderful bamboo smell that would emanate from the case when opened, but alas, those volatiles are gone.
View attachment 1059173
View attachment 1059174
And I still occasionally use this old adding machine to balance my checkbook
View attachment 1059175
However, I have gotten so stupid that I find it easier to use web calculators for tasks that I used to do on paper.
Just as no one today would think of using a slide rule at college, or at work, no living engineer in sound mind and body would use those low grade steels used in those vintage receivers and bolts, in safety critical applications. Incidentally, I recently purchased a $60.00 transmission flywheel. Talked to the manufacturer and they use 4340 steel. I would have liked to talked to a metallurgist and asked his opinion about using 1035 steel as a flywheel material.
I have seen at the range one Krag bolt that was cracked at the lug. The owner was still shooting the thing! These old Krags should not be pushed beyond period pressures. The 30-40 Krag cartridge, in a Ruger #1, can be loaded to the same pressures as any modern cartridge, because Ruger #1’s are made of modern alloy steels. But when you get into vintage, pre vacuum tube technologies, one should be cautious. You just don’t know how strong the action materials, and how much lifetime is left before the bolt lugs crack.