The information I have from Foundry Industry Research in Australia is that NiHard 1 and 2 may be heat treated at 250-300C for 4 to 16 hours or 4 to 6 hours at 425-475C followed by 4 to 16 hours at 250-300C. This treatmentis "designed to stress relieve the casting and temper the martensite formed...
We have cut reasonably large 27% chromium white iron parts using water jet cutting followed by conventional grinding and polishing to look at macrosections through weld repairs.
We are dealing with a road tanker for compressed gas and the documentation indicates it was manufcatured in Texas in 1966. The material used was steel noted as "Case 1298 FBX". I understand that the FBX is firebox steel but does anyone know what the material properties are (tensile and...
Here in Australia we have standards AS1554 parts 1 to 6 covering the welding of all types of steel. Part 1 gives guidelines on the Carbon Eqivalent calculation giving a Group number and the relationship between this and combined joint thickness,joint weldability index,arc energy and minimum...
I think that kpeddie01 may be referring to the flotation of graphite nodules in large nodular (or spheroidal graphite) iron castings. This is particularly common in large castings used for gear manufacture for ore grinding mills. Because of its prevalence the gears are often machined such that...
The Equotip by Proceq is recognized in ASTM as A956 (Leeb Hardness testing). Sticking to the procedures outlined in the standard and the Instructions will give accurate results from this type of tester. It is only when people do not stick to instructions on cleanliness of the impact device and...
Is the steel being used for the blades one which should be preheated before laser cutting? Preheating reduces the quench rate after cutting and serves to temper the hardened zone in the heat affected zone.
I am interested in the so-called "barberpoling" effect produced on items which have been induction hardened. I understand that it is produced either by poor inductor design, non rotation of the part during hardening or quenching inadequacies.
My question relates to the effect on fatigue...
Be careful with German steel designations.
There is a big difference between 20Mn6V and 20MnV6. The V after the grade designation indicates that the steel is quenched and tempered and does not have an intentional vanadium addition.
Does anyone have references which detail the problems of austenitic stainless steels and fluorine compounds?
I have an aluminum smelter client who was attempting to change from carbon steel to austenitic stainless for a gas scrubber from the anode bake ovens. The gas contains all sorts of...
The other factor which may affect impact properties is the reduction from the ingot during forging. The higher the better. Depending on the size of the finished forging a minimum reduction of four to one from the ingot would be necessary.
Are you sure that the steel's designation is not 50Mn7?
50Mn7 is a standard German steel somewhat like AISI1552 but with manganese in the range 1.60-2.00%.
Be aware of the possibility of hydrogen embrittlement of these high strength steels during the acid pickling process prior to hot dipping.
Your galvanizer needs to be on top of the acid bath chemistry with the correct inhibitor level to prevent hydrogen formation.
"Delamination of old steel" is a bit of a furphy.
More likely to be caustic stress corrosion cracking as identified in the HAZ areas previously.
It is sometimes worth investigating for other welds in the zone of the crack if it appears in a "strange" area. Previous weld repairs may have been...
According to my information there should not be anything between the two steels.
Assuming you need a 2 inch square, the equivalent round bar is 2 1/2 inch and this is the limiting ruling section (diameter which will transform to martensite on quenching) for 4140 while 4340 is good for 4 inches...