FP-96 English Version - Eastern Federal Lands Highway Division

Section 555Table 555-5Heat Straightening TemperaturesMaterial to be StraightenedGrade 70W > 6 inches from weldGrade 70W < 6 inches from weldGrade 100 or 100W > 6 inches from weldGrade 100 or 100W < 6 inches from weldMaximum Temperature1,075 bF900 bF1,125 bF950 bFIn all the other steels, do not exceed 1,200 bF in the heated area. Control theapplication by temperature-indicating crayons, liquids, or bimetal thermometers.Keep parts to be heat straightened and substantially free of external forcesand stress, except stresses resulting from mechanical means used in conjunctionwith the application of heat.Evidence of fracture following straightening of a bend or buckle will because for rejection of the damaged piece.555.09 Annealing and Stress Relieving. Machine, finish bore, and s-traighten annealed or normalized structural members after heat treatment.Normalize and anneal (full annealing) according to ASTM A 919. Maintainuniform temperatures throughout the furnace during the heating and coolingso that the temperature at no two points on the member will differ by morethan 100 bF at any one time.Do not anneal or normalize members of grades 100/100W or 70W steels.Stress relieve these grades only with approval.Record each furnace charge, identify the pieces in the charge and show thetemperatures and schedule actually used. Provide proper instruments, includingrecording pyrometers, for determining at any time the temperatures ofmembers in the furnace. Make records of the treatment operation available forapproval. The maximum allowed holding temperature for stress relievinggrades 100/100W and grade 70W steels is 1,125 bF and 1,075 bF, respectively.434