Heat treatment process, bending L, under the following conditions, cold or hot bending heat treatment steel pipe specified in Table 4 must be carried out. Heat treatment process, bending L, under the following conditions, cold-rolled steel pipe must be carried out hot bending heat treatment specified in Table 4. Heat treatment process, bending L, under the following conditions, cold or hot bending heat treatment steel pipe specified in Table 4 must be carried out.
