I dont know to much about the GM diesel line but i suppose it would be worth looking into as well for production, I have done extensive reading into applications of different alloys including inconel and it appears to me that they are using the alloy 713c inconel which is casted first and then machined later, the enviroment they operate in is a high thermal shock enviroment and from what i can tell 713c inconel isnt the greatest at handling immediate thermal shock which happens as the injector sprays wet fuel on the hot precup in the process of combustion, although it retains a very hard tensile strength for prolonged periods of heat the thermal shock seems to be what kills it, i have tig welded the inconel precups adding high nickel content to them and they seem fine now after the high amount of nickel, they say the exhaust temperature gets up to 1200 degrees Fahrenheit tops, but that doesnt mean the precups are at that heat, i was going to figure they would be around or a little higher in temperature than the coolant temp, there are many stainless steel alloys which can handle high heat/stress /thermal shock applications and resist intergranular corrosion as well as scaling in the long run of thermal cycles, i need to do testing but if my calculations are right it looks like i could replace the expensive inconel precups that constantly crack with a much more stable metal, but tbh there is only one way to find out so i have to do testing, let me know what you guys think i would like to hear some input from you all
